This version is in beta - expect some breaking changes.

Individual Losses (MTD) API

Version and status
Available in Sandbox	Yes
Sandbox base URL	https://test-api.service.hmrc.gov.uk
Available in Production	Yes
Production base URL	https://api.service.hmrc.gov.uk

Overview

This API allows developers to provide financial data for Brought Forward Losses and Loss Claims.

For Brought Forward losses a developer can:

• provide a list of brought forward losses
• create a new brought forward loss
• show a single brought forward loss
• update an existing brought forward loss
• delete an existing brought forward loss

For Loss claims a developer can:

• provide a list of loss claims
• create a loss claim against an income source for a specific tax year
• show the detail of an existing loss claim
• update a previously entered loss claim
• delete an existing loss claim

For information on how to connect to this API see the Income Tax MTD end-to-end service guide .

Send fraud prevention data

HMRC monitors transactions to help protect your customers' confidential data from criminals and fraudsters.

Warning You are required by law to submit header data for this API. This includes all associated APIs and endpoints.

Check the data you need to send. You can also use the Test API during initial development and as part of your quality assurance checks.

Versioning

When an API changes in a way that is backwards-incompatible, we increase the version number of the API. See our reference guide for more on versioning.

Errors

We use standard HTTP status codes to show whether an API request succeeded or not. They are usually in the range:

• 200 to 299 if it succeeded, including code 202 if it was accepted by an API that needs to wait for further action
• 400 to 499 if it failed because of a client error by your application
• 500 to 599 if it failed because of an error on our server

Errors specific to each API are shown in the Endpoints section, under Response. See our reference guide for more on errors.

Single errors will be returned in the following format:
{     "code": "FORMAT_FIELD_NAME",     "message": "The provided FieldName is invalid" }

Where possible, multiple errors will be returned with INVALID_REQUEST in the following format:
{     "code": "INVALID_REQUEST",     "message": "Invalid request",     "errors": [         {      "code": "RULE_FIELD_NAME",      "message": "The provided FieldName is not allowed"         },         {      "code": "FORMAT_FIELD_NAME",      "message": "The provided FieldName is invalid"         }     ] }

Where it is possible for the same error to be returned multiple times, message will describe the expected format and paths will show the fields which are invalid.

Where arrays are submitted a number indicates the object in the array sequence, for example, /arrayName/1/fieldName.

An example with single error:
{     "code": "FORMAT_STRING_NAME",     "message": "The provided field is not valid",     "paths": [ "/arrayName/0/fieldName" ] }

An example with multiple errors:
{     "code": "INVALID_REQUEST",     "message": "Invalid request",     "errors": [      {      "code": "FORMAT_VALUE",      "message": "The value should be between 0 and 99999999999.99",      "paths": [ "/objectName/fieldName1", "/arrayName/0/fieldName2" ]      },      {      "code": "FORMAT_STRING_NAME",      "message": "The provided field is not valid",      "paths": [ "/arrayName/0/fieldName3", "/arrayName/1/fieldName3" ]      }     ] }

Changelog

You can find the changelog in the income-tax-mtd-changelog GitHub wiki.

Support

• Raise non-technical or platform-related issues with the Software Development Support Team (SDST).
• Raise technical issues on the income-tax-mtd-changelog GitHub page.

Testing

You can use the sandbox environment to test this API. You can use the Create Test User API or it's frontend service to create test users.

It may not be possible to test all scenarios in the sandbox. You can test some scenarios by passing the Gov-Test-Scenario header. Documentation for each endpoint includes a Test data section, which explains the scenarios that you can simulate using the Gov-Test-Scenario header.

If you have a specific testing need that is not supported in the sandbox, contact our support team.

Some APIs may be marked [test only]. This means that they are not available for use in production and may change.

Skip to main content

Endpoints

Brought Forward Losses

Resources related to a customer’s financial data for their brought forward losses.

Brought Forward Losses resources

/individuals/losses/{nino}/brought-forward-losses

List Brought Forward Losses

GET

This endpoint allows a developer to retrieve a list of all brought forward losses that have incurred before joining MTD. A National Insurance number must be provided.

Authorisation

This endpoint is user-restricted and requires an Authorization header containing an OAuth 2.0 Bearer Token with the read:self-assessment scope.

Path parameters

Name	Description
nino string required	National Insurance number, in the format AA999999A. For example: TC663795B

Query parameters

Name	Description
businessId string optional	An identifier for the business, unique to the customer. Must conform to the regular expression ^X[A-Z0-9]{1}IS[0-9]{11}$ For example: XBIS00000001319
typeOfLoss string optional	The type of business the loss applies to. Limited to the following possible values: self-employment uk-property-fhl uk-property-non-fhl foreign-property-fhl-eea foreign-property
taxYearBroughtForwardFrom string optional	The tax year to which the loss applies. The start year and end year must not span two tax years. No gaps are allowed, for example, 2020-22 is not valid. The minimum tax year is 2018-19. The tax year must have ended. For example: 2022-23

Request headers

Name	Description
Accept required	Specifies the response format and the version of the API to be used. For example: application/vnd.hmrc.3.0+json
Gov-Test-Scenario optional	Only in sandbox environment. See Test Data table for all header values. For example: -
Authorization required	An OAuth 2.0 Bearer Token with the read:self-assessment scope. For example: Bearer bb7fed3fe10dd235a2ccda3d50fb

See also fraud prevention.

Responses

HTTP status 200 (OK)

Response headers

Name	Description
X-CorrelationId required	Unique ID for operation tracking String, 36 characters. For example: c75f40a6-a3df-4429-a697-471eeec46435

See also fraud prevention.

{
  "losses": [
    {
      "lossId": "A2Za0911235813a",
      "businessId": "XBIS12345678901",
      "typeOfLoss": "self-employment",
      "lossAmount": 9420.01,
      "taxYearBroughtForwardFrom": "2021-22",
      "lastModified": "2022-12-02T11:55:55.763Z",
      "links": [
        {
          "href": "/individuals/losses/TC663795B/brought-forward-losses/A2Za0911235813a",
          "rel": "self",
          "method": "GET"
        }
      ]
    },
    {
      "lossId": "A2Za0911235813b",
      "businessId": "XBIS12345678902",
      "typeOfLoss": "self-employment-class4",
      "lossAmount": 3298.50,
      "taxYearBroughtForwardFrom": "2021-22",
      "lastModified": "2022-12-03T11:55:55.763Z",
      "links": [
        {
          "href": "/individuals/losses/TC663795B/brought-forward-losses/A2Za0911235813b",
          "rel": "self",
          "method": "GET"
        }
      ]
    },
    {
      "lossId": "A2Za0911235813c",
      "businessId": "XPIS12345678903",
      "typeOfLoss": "uk-property-fhl",
      "lossAmount": 1882.99,
      "taxYearBroughtForwardFrom": "2021-22",
      "lastModified": "2022-12-04T11:55:55.763Z",
      "links": [
        {
          "href": "/individuals/losses/TC663795B/brought-forward-losses/A2Za0911235813c",
          "rel": "self",
          "method": "GET"
        }
      ]
    },
    {
      "lossId": "A2Za0911235813d",
      "businessId": "XPIS12345678904",
      "typeOfLoss": "uk-property-non-fhl",
      "lossAmount": 4882.99,
      "taxYearBroughtForwardFrom": "2021-22",
      "lastModified": "2022-12-05T11:55:55.763Z",
      "links": [
        {
          "href": "/individuals/losses/TC663795B/brought-forward-losses/A2Za0911235813d",
          "rel": "self",
          "method": "GET"
        }
      ]
    },
    {
      "lossId": "A2Za0911235813e",
      "businessId": "XFIS12345678905",
      "typeOfLoss": "foreign-property-fhl-eea",
      "lossAmount": 2985.99,
      "taxYearBroughtForwardFrom": "2021-22",
      "lastModified": "2022-12-06T11:55:55.763Z",
      "links": [
        {
          "href": "/individuals/losses/TC663795B/brought-forward-losses/A2Za0911235813e",
          "rel": "self",
          "method": "GET"
        }
      ]
    },
    {
      "lossId": "A2Za0911235813f",
      "businessId": "XFIS12345678906",
      "typeOfLoss": "foreign-property",
      "lossAmount": 3553.99,
      "taxYearBroughtForwardFrom": "2021-22",
      "lastModified": "2022-12-07T11:55:55.763Z",
      "links": [
        {
          "href": "/individuals/losses/TC663795B/brought-forward-losses/A2Za0911235813f",
          "rel": "self",
          "method": "GET"
        }
      ]
    }
  ],
  "links": [
    {
      "href": "/individuals/losses/TC663795B/brought-forward-losses",
      "rel": "create-brought-forward-loss",
      "method": "POST"
    },
    {
      "href": "/individuals/losses/TC663795B/brought-forward-losses",
      "rel": "self",
      "method": "GET"
    }
  ]
}

Name	Description
losses array required	Array of losses. An empty array will never be returned. In the instance that no losses exist for the supplied NINO, a MATCHING_RESOURCE_NOT_FOUND error will be returned.
lossId string required	The unique identifier of the loss. Must conform to the regular expression ^[A-Za-z0-9]{15}$ For example: 1234568790ABCDE
businessId string required	An identifier for the business, unique to the customer. Must conform to the regular expression ^X[A-Z0-9]{1}IS[0-9]{11}$ For example: XPIS12345678910
typeOfLoss string required	The type of business the loss applies to. Limited to the following possible values: self-employment self-employment-class4 uk-property-fhl uk-property-non-fhl foreign-property-fhl-eea foreign-property
lossAmount number required	Brought Forward Loss amount related to the type of loss specified. The value must be between 0 and 99999999999.99 up to 2 decimal places. For example: 5000.99
taxYearBroughtForwardFrom string required	The tax year to which the loss applies. The start year and end year must not span two tax years. No gaps are allowed, for example, 2020-22 is not valid. The minimum tax year is 2018-19. The tax year must have ended. For example: 2022-23
lastModified string required	The timestamp when the entry was created or last modified. Must conform to the regular expression ^2[0-9]{3}-[0-9]{2}-[0-9]{2}T[0-9]{2}:[0-9]{2}:[0-9]{2}(\.[0-9]{0,3}|)Z$ For example: 2021-07-13T12:13:48.763Z
links array optional	A list of endpoint links that indicate possible actions related to the current resource.
href string required	The relative url of the endpoint. For example: /individuals/losses/TC663795B/brought-forward-losses/A2Za0911235813a
rel string required	A label for the endpoint, which describes how it is related to the current resource. The rel will be self where the action is retrieval of the same resource. Limited to the following possible values: self
method string required	The HTTP method type for the endpoint. Limited to the following possible values: GET
links array optional	A list of endpoint links that indicate possible actions related to the current resource.
href string required	The relative url of the endpoint. For example: /individuals/losses/TC663795B/brought-forward-losses
rel string required	A label for the endpoint, which describes how it is related to the current resource. The rel will be self where the action is retrieval of the same resource. Limited to the following possible values: self create-brought-forward-loss
method string required	The HTTP method type for the endpoint. Limited to the following possible values: GET POST

Error scenarios

Scenario	HTTP status	Code
The format of the supplied NINO field is not valid.	400 (Bad Request)	FORMAT_NINO
The format of the supplied tax year field is not valid.	400 (Bad Request)	FORMAT_TAX_YEAR
Tax year range invalid. A tax year range of one year is required.	400 (Bad Request)	RULE_TAX_YEAR_RANGE_INVALID
The specified tax year is not supported. That is, the tax year specified is before the minimum tax year value.	400 (Bad Request)	RULE_TAX_YEAR_NOT_SUPPORTED
The format of the supplied Business ID field is not valid.	400 (Bad Request)	FORMAT_BUSINESS_ID
The format of the supplied type of loss field is not valid.	400 (Bad Request)	FORMAT_TYPE_OF_LOSS
The client or agent is not authorised. This is because: the client is not subscribed to MTD, the agent is not subscribed to Agent Services, or the client has not authorised the agent to act on their behalf.	403 (Forbidden)	CLIENT_OR_AGENT_NOT_AUTHORISED
Matching resource not found.	404 (Not Found)	MATCHING_RESOURCE_NOT_FOUND

For error scenarios that are common across all APIs, and for error formats, see our reference guide.

Test data

Scenario simulations using Gov-Test-Scenario headers is only available in the sandbox environment.

Header Value (Gov-Test-Scenario)	Scenario
N/A - DEFAULT	Simulates success response with multiple business types.
SELF_EMPLOYMENT	Simulates success response with only self-employment.
UK_PROPERTY	Simulates success response with only UK property.
FOREIGN_PROPERTY	Simulates success response with only foreign property.
NOT_FOUND	Simulates the scenario where no data is found.

Close Section

/individuals/losses/{nino}/brought-forward-losses

Create a Brought Forward Loss

POST

This endpoint allows the developer to create a new brought forward loss which can be submitted against self-employment, self-employment class 4, UK Furnished Holiday Let (FHL) property, UK other (Non-FHL) property, foreign property FHL in the European Economic Area (EEA) and foreign property for the tax year prior to joining MTD. A National Insurance number must be provided.

Authorisation

This endpoint is user-restricted and requires an Authorization header containing an OAuth 2.0 Bearer Token with the write:self-assessment scope.

Path parameters

Name	Description
nino string required	National Insurance number, in the format AA999999A. For example: TC663795B

Request headers

Name	Description
Accept required	Specifies the response format and the version of the API to be used. For example: application/vnd.hmrc.3.0+json
Content-Type required	Specifies the format of the request body, which must be JSON. For example: application/json
Gov-Test-Scenario optional	Only in sandbox environment. See Test Data table for all header values. For example: -
Authorization required	An OAuth 2.0 Bearer Token with the write:self-assessment scope. For example: Bearer bb7fed3fe10dd235a2ccda3d50fb

See also fraud prevention.

Request

Scenario: Self-Employment Request

{
  "taxYearBroughtForwardFrom": "2020-21",
  "businessId": "XBIS12345678910",
  "typeOfLoss": "self-employment",
  "lossAmount": 5001.99
}

Scenario: UK FHL Property Request

{
  "taxYearBroughtForwardFrom": "2020-21",
  "businessId": "XPIS12345678910",
  "typeOfLoss": "uk-property-fhl",
  "lossAmount": 500.99
}

Scenario: Foreign Property Request

{
  "taxYearBroughtForwardFrom": "2020-21",
  "businessId": "XFIS12345678910",
  "typeOfLoss": "foreign-property",
  "lossAmount": 5000.99
}

Name	Description
taxYearBroughtForwardFrom string required	The tax year to which the loss applies. The start year and end year must not span two tax years. No gaps are allowed, for example, 2020-22 is not valid. The minimum tax year is 2018-19. The tax year must have ended. For example: 2020-21
typeOfLoss string required	The type of business the loss applies to. Limited to the following possible values: self-employment self-employment-class4 uk-property-fhl uk-property-non-fhl foreign-property-fhl-eea foreign-property
businessId string required	An identifier for the business, unique to the customer. Must conform to the regular expression ^X[A-Z0-9]{1}IS[0-9]{11}$ For example: XPIS12345678910
lossAmount number required	Brought Forward Loss amount related to the type of loss specified. The value must be between 0 and 99999999999.99 up to 2 decimal places. For example: 2345.67

Responses

HTTP status 201 (Created)

Response headers

Name	Description
X-CorrelationId required	Unique ID for operation tracking String, 36 characters. For example: c75f40a6-a3df-4429-a697-471eeec46435

See also fraud prevention.

{
  "lossId": "AAZZ1234567890a",
  "links": [
    {
      "href": "/individuals/losses/TC663795B/brought-forward-losses/AAZZ1234567890a",
      "rel": "self",
      "method": "GET"
    },
    {
      "href": "/individuals/losses/TC663795B/brought-forward-losses/AAZZ1234567890a/change-loss-amount",
      "rel": "amend-brought-forward-loss",
      "method": "POST"
    },
    {
      "href": "/individuals/losses/TC663795B/brought-forward-losses/AAZZ1234567890a",
      "rel": "delete-brought-forward-loss",
      "method": "DELETE"
    }
  ]
}

Name	Description
lossId string required	The unique identifier of the loss. Must conform to the regular expression ^[A-Za-z0-9]{15}$ For example: AAZZ1234567890a
links array optional	A list of endpoint links that indicate possible actions related to the current resource.
href string required	The relative url of the endpoint. For example: /individuals/losses/TC663795B/brought-forward-losses/AAZZ1234567890a
rel string required	A label for the endpoint, which describes how it is related to the current resource. The rel will be self where the action is retrieval of the same resource. Limited to the following possible values: self amend-brought-forward-loss delete-brought-forward-loss
method string required	The HTTP method type for the endpoint. Limited to the following possible values: GET POST DELETE

Error scenarios

Scenario	HTTP status	Code
The format of the supplied NINO field is not valid.	400 (Bad Request)	FORMAT_NINO
The format of the supplied tax year field is not valid.	400 (Bad Request)	FORMAT_TAX_YEAR
Tax year range invalid. A tax year range of one year is required.	400 (Bad Request)	RULE_TAX_YEAR_RANGE_INVALID
The specified tax year is not supported. That is, the tax year specified is before the minimum tax year value.	400 (Bad Request)	RULE_TAX_YEAR_NOT_SUPPORTED
One or more values have been added with the incorrect format.	400 (Bad Request)	FORMAT_VALUE
The format of the supplied Business ID field is not valid.	400 (Bad Request)	FORMAT_BUSINESS_ID
An empty or non-matching body was submitted.	400 (Bad Request)	RULE_INCORRECT_OR_EMPTY_BODY_SUBMITTED
The format of the supplied type of loss field is not valid.	400 (Bad Request)	FORMAT_TYPE_OF_LOSS
The submission has been made before the tax year it relates to has ended.	400 (Bad Request)	RULE_TAX_YEAR_NOT_ENDED
The remote endpoint has indicated that the submission already exists for this resource.	403 (Forbidden)	RULE_DUPLICATE_SUBMISSION
The client or agent is not authorised. This is because: the client is not subscribed to MTD, the agent is not subscribed to Agent Services, or the client has not authorised the agent to act on their behalf.	403 (Forbidden)	CLIENT_OR_AGENT_NOT_AUTHORISED
The supplied income source could not be found.	404 (Not Found)	MATCHING_RESOURCE_NOT_FOUND

For error scenarios that are common across all APIs, and for error formats, see our reference guide.

Test data

Scenario simulations using Gov-Test-Scenario headers is only available in the sandbox environment.

Header Value (Gov-Test-Scenario)	Scenario
N/A - DEFAULT	Simulates success response.
NOT_FOUND	Simulates the scenario where no data is found.
DUPLICATE_SUBMISSION	Simulates the scenario where a duplicated loss is found.

Close Section

/individuals/losses/{nino}/brought-forward-losses/{lossId}

Retrieve a Brought Forward Loss

GET

This endpoint allows the developer to retrieve an existing brought forward loss amount. A National Insurance number and Loss ID must be provided.

Authorisation

This endpoint is user-restricted and requires an Authorization header containing an OAuth 2.0 Bearer Token with the read:self-assessment scope.

Path parameters

Name	Description
nino string required	National Insurance number, in the format AA999999A. For example: TC663795B
lossId string required	A unique identifier for loss. Must conform to the regular expression ^[A-Za-z0-9]{15}$ For example: AAZZ1234567890a

Request headers

Name	Description
Accept required	Specifies the response format and the version of the API to be used. For example: application/vnd.hmrc.3.0+json
Gov-Test-Scenario optional	Only in sandbox environment. See Test Data table for all header values. For example: -
Authorization required	An OAuth 2.0 Bearer Token with the read:self-assessment scope. For example: Bearer bb7fed3fe10dd235a2ccda3d50fb

See also fraud prevention.

Responses

HTTP status 200 (OK)

Response headers

Name	Description
X-CorrelationId required	Unique ID for operation tracking String, 36 characters. For example: c75f40a6-a3df-4429-a697-471eeec46435

See also fraud prevention.

Self-Employment Loss

{
  "businessId": "XBIS12345678911",
  "typeOfLoss": "self-employment",
  "lossAmount": 300.11,
  "taxYearBroughtForwardFrom": "2021-22",
  "lastModified": "2022-11-05T11:56:27Z",
  "links": [
    {
      "href": "/individuals/losses/TC663795B/brought-forward-losses/AAZZ1234567890a",
      "rel": "self",
      "method": "GET"
    },
    {
      "href": "/individuals/losses/TC663795B/brought-forward-losses/AAZZ1234567890a/change-loss-amount",
      "rel": "amend-brought-forward-loss",
      "method": "POST"
    },
    {
      "href": "/individuals/losses/TC663795B/brought-forward-losses/AAZZ1234567890a",
      "rel": "delete-brought-forward-loss",
      "method": "DELETE"
    }
  ]
}

UK FHL Property Loss

{
  "businessId": "XPIS12345678912",
  "typeOfLoss": "uk-property-fhl",
  "lossAmount": 423.32,
  "taxYearBroughtForwardFrom": "2021-22",
  "lastModified": "2022-12-02T12:56:58Z",
  "links": [
    {
      "href": "/individuals/losses/TC663795B/brought-forward-losses/AAZZ1234567890a",
      "rel": "self",
      "method": "GET"
    },
    {
      "href": "/individuals/losses/TC663795B/brought-forward-losses/AAZZ1234567890a/change-loss-amount",
      "rel": "amend-brought-forward-loss",
      "method": "POST"
    },
    {
      "href": "/individuals/losses/TC663795B/brought-forward-losses/AAZZ1234567890a",
      "rel": "delete-brought-forward-loss",
      "method": "DELETE"
    }
  ]
}

Foreign Property Loss

{
  "businessId": "XFIS12345678913",
  "typeOfLoss": "foreign-property",
  "lossAmount": 553.32,
  "taxYearBroughtForwardFrom": "2021-22",
  "lastModified": "2022-12-02T11:55:55Z",
  "links": [
    {
      "href": "/individuals/losses/TC663795B/brought-forward-losses/AAZZ1234567890a",
      "rel": "self",
      "method": "GET"
    },
    {
      "href": "/individuals/losses/TC663795B/brought-forward-losses/AAZZ1234567890a/change-loss-amount",
      "rel": "amend-brought-forward-loss",
      "method": "POST"
    },
    {
      "href": "/individuals/losses/TC663795B/brought-forward-losses/AAZZ1234567890a",
      "rel": "delete-brought-forward-loss",
      "method": "DELETE"
    }
  ]
}

Name	Description
businessId string required	An identifier for the business, unique to the customer. Must conform to the regular expression ^X[A-Z0-9]{1}IS[0-9]{11}$ For example: XAIS12345678910
typeOfLoss string required	The type of business the loss applies to. Limited to the following possible values: self-employment self-employment-class4 uk-property-fhl uk-property-non-fhl foreign-property-fhl-eea foreign-property
lossAmount number required	Brought Forward Loss amount related to the type of loss specified. The value must be between 0 and 99999999999.99 up to 2 decimal places. For example: 5000.99
taxYearBroughtForwardFrom string required	The tax year to which the loss applies. The start year and end year must not span two tax years. No gaps are allowed, for example, 2020-22 is not valid. The minimum tax year is 2018-19. The tax year must have ended. For example: 2022-23
lastModified string required	The timestamp when the entry was created or last modified. Must conform to the regular expression ^2[0-9]{3}-[0-9]{2}-[0-9]{2}T[0-9]{2}:[0-9]{2}:[0-9]{2}(\.[0-9]{0,3}|)Z$ For example: 2020-07-13T12:13:48.763Z
links array optional	A list of endpoint links that indicate possible actions related to the current resource.
href string required	The relative url of the endpoint. For example: /individuals/losses/TC663795B/brought-forward-losses/AAZZ1234567890a
rel string required	A label for the endpoint, which describes how it is related to the current resource. The rel will be self where the action is retrieval of the same resource. Limited to the following possible values: self amend-brought-forward-loss delete-brought-forward-loss
method string required	The HTTP method type for the endpoint. Limited to the following possible values: GET POST DELETE

Error scenarios

Scenario	HTTP status	Code
The format of the supplied NINO field is not valid.	400 (Bad Request)	FORMAT_NINO
The format of the supplied Loss ID is not valid.	400 (Bad Request)	FORMAT_LOSS_ID
The client or agent is not authorised. This is because: the client is not subscribed to MTD, the agent is not subscribed to Agent Services, or the client has not authorised the agent to act on their behalf.	403 (Forbidden)	CLIENT_OR_AGENT_NOT_AUTHORISED
The remote endpoint has indicated that no data can be found for the given loss ID.	404 (Not Found)	MATCHING_RESOURCE_NOT_FOUND

For error scenarios that are common across all APIs, and for error formats, see our reference guide.

Test data

Scenario simulations using Gov-Test-Scenario headers is only available in the sandbox environment.

Header Value (Gov-Test-Scenario)	Scenario
N/A - DEFAULT	Simulates success response where type of loss is Self-Employment.
UK_PROPERTY	Simulates the scenario where type of loss is UK Property FHL.
FOREIGN_PROPERTY	Simulates the scenario where type of loss is Foreign Property.
NOT_FOUND	Simulates the scenario where no data is found.

Close Section

/individuals/losses/{nino}/brought-forward-losses/{lossId}

Delete a Brought Forward Loss

DELETE

This endpoint allows a developer to delete an existing brought forward loss. A National Insurance number and Loss ID must be provided. The user should be aware that where a loss has been used as part of a successful final declaration activity, deletion will be blocked and an error code will be returned. In such a case, the user can amend the loss amount to zero.

Authorisation

This endpoint is user-restricted and requires an Authorization header containing an OAuth 2.0 Bearer Token with the write:self-assessment scope.

Path parameters

Name	Description
nino string required	National Insurance number, in the format AA999999A. For example: TC663795B
lossId string required	A unique identifier for loss. Must conform to the regular expression ^[A-Za-z0-9]{15}$ For example: AAZZ1234567890a

Request headers

Name	Description
Accept required	Specifies the response format and the version of the API to be used. For example: application/vnd.hmrc.3.0+json
Gov-Test-Scenario optional	Only in sandbox environment. See Test Data table for all header values. For example: -
Authorization required	An OAuth 2.0 Bearer Token with the write:self-assessment scope. For example: Bearer bb7fed3fe10dd235a2ccda3d50fb

See also fraud prevention.

Responses

HTTP status 204 (No Content)

Response headers

Name	Description
X-CorrelationId required	Unique ID for operation tracking String, 36 characters. For example: c75f40a6-a3df-4429-a697-471eeec46435

See also fraud prevention.

Error scenarios

Scenario	HTTP status	Code
The format of the supplied NINO field is not valid.	400 (Bad Request)	FORMAT_NINO
The format of the supplied Loss ID is not valid.	400 (Bad Request)	FORMAT_LOSS_ID
The client or agent is not authorised. This is because: the client is not subscribed to MTD, the agent is not subscribed to Agent Services, or the client has not authorised the agent to act on their behalf.	403 (Forbidden)	CLIENT_OR_AGENT_NOT_AUTHORISED
The remote endpoint has indicated that the requested resource has been locked.	403 (Forbidden)	RULE_DELETE_AFTER_FINAL_DECLARATION
The remote endpoint has indicated that no data can be found for the given loss ID.	404 (Not Found)	MATCHING_RESOURCE_NOT_FOUND

For error scenarios that are common across all APIs, and for error formats, see our reference guide.

Test data

Scenario simulations using Gov-Test-Scenario headers is only available in the sandbox environment.

Header Value (Gov-Test-Scenario)	Scenario
N/A - DEFAULT	Simulates success response.
DELETE_AFTER_FINAL_DECLARATION	Simulates the error scenario where the user has already submitted a final declaration for this tax year.
NOT_FOUND	Simulates the scenario where no data is found.

Close Section

/individuals/losses/{nino}/brought-forward-losses/{lossId}/change-loss-amount

Amend a Brought Forward Loss Amount

POST

This endpoint allows the developer to update an existing brought forward loss amount. A National Insurance number and Loss ID must be provided.

Authorisation

This endpoint is user-restricted and requires an Authorization header containing an OAuth 2.0 Bearer Token with the write:self-assessment scope.

Path parameters

Name	Description
nino string required	National Insurance number, in the format AA999999A. For example: TC663795B
lossId string required	A unique identifier for loss. Must conform to the regular expression ^[A-Za-z0-9]{15}$ For example: AAZZ1234567890a

Request headers

Name	Description
Accept required	Specifies the response format and the version of the API to be used. For example: application/vnd.hmrc.3.0+json
Content-Type required	Specifies the format of the request body, which must be JSON. For example: application/json
Gov-Test-Scenario optional	Only in sandbox environment. See Test Data table for all header values. For example: -
Authorization required	An OAuth 2.0 Bearer Token with the write:self-assessment scope. For example: Bearer bb7fed3fe10dd235a2ccda3d50fb

See also fraud prevention.

Request

{
  "lossAmount": 3456.78
}

Name	Description
lossAmount number required	Brought Forward Loss amount related to the type of loss specified. The value must be between 0 and 99999999999.99 up to 2 decimal places. For example: 5000.99

Responses

HTTP status 200 (OK)

Response headers

Name	Description
X-CorrelationId required	Unique ID for operation tracking String, 36 characters. For example: c75f40a6-a3df-4429-a697-471eeec46435

See also fraud prevention.

Self-Employment Class 4 Loss

{
  "businessId": "XBIS12345678910",
  "typeOfLoss": "self-employment-class4",
  "lossAmount": 3456.78,
  "taxYearBroughtForwardFrom": "2021-22",
  "lastModified": "2022-07-13T12:13:48.763Z",
  "links": [
    {
      "href": "/individuals/losses/TC663795B/brought-forward-losses/AAZZ1234567890a",
      "rel": "self",
      "method": "GET"
    },
    {
      "href": "/individuals/losses/TC663795B/brought-forward-losses/AAZZ1234567890a/change-loss-amount",
      "rel": "amend-brought-forward-loss",
      "method": "POST"
    },
    {
      "href": "/individuals/losses/TC663795B/brought-forward-losses/AAZZ1234567890a",
      "rel": "delete-brought-forward-loss",
      "method": "DELETE"
    }
  ]
}

UK Non-FHL Property Loss

{
  "businessId": "XPIS12345678910",
  "typeOfLoss": "uk-property-non-fhl",
  "lossAmount": 3456.78,
  "taxYearBroughtForwardFrom": "2021-22",
  "lastModified": "2022-07-13T12:13:48.763Z",
  "links": [
    {
      "href": "/individuals/losses/TC663795B/brought-forward-losses/AAZZ1234567890a",
      "rel": "self",
      "method": "GET"
    },
    {
      "href": "/individuals/losses/TC663795B/brought-forward-losses/AAZZ1234567890a/change-loss-amount",
      "rel": "amend-brought-forward-loss",
      "method": "POST"
    },
    {
      "href": "/individuals/losses/TC663795B/brought-forward-losses/AAZZ1234567890a",
      "rel": "delete-brought-forward-loss",
      "method": "DELETE"
    }
  ]
}

Name	Description
businessId string required	An identifier for the business, unique to the customer. Must conform to the regular expression ^X[A-Z0-9]{1}IS[0-9]{11}$ For example: XAIS12345678910
typeOfLoss string required	The type of business the loss applies to. Limited to the following possible values: self-employment self-employment-class4 uk-property-fhl uk-property-non-fhl foreign-property-fhl-eea foreign-property
lossAmount number required	Brought Forward Loss amount related to the type of loss specified. The value must be between 0 and 99999999999.99 up to 2 decimal places. For example: 12345.67
taxYearBroughtForwardFrom string required	The tax year to which the loss applies. The start year and end year must not span two tax years. The minimum tax year is 2018-19. No gaps are allowed, for example, 2022-24 is not valid. For example: 2018-19
lastModified string required	The timestamp when the entry was created or last modified. Must conform to the regular expression ^2[0-9]{3}-[0-9]{2}-[0-9]{2}T[0-9]{2}:[0-9]{2}:[0-9]{2}(\.[0-9]{0,3}|)Z$ For example: 2020-07-13T12:13:48.763Z
links array optional	A list of endpoint links that indicate possible actions related to the current resource.
href string required	The relative url of the endpoint. For example: /individuals/losses/TC663795B/brought-forward-losses/AAZZ1234567890a
rel string required	A label for the endpoint, which describes how it is related to the current resource. The rel will be self where the action is retrieval of the same resource. Limited to the following possible values: self amend-brought-forward-loss delete-brought-forward-loss
method string required	The HTTP method type for the endpoint. Limited to the following possible values: GET POST DELETE

Error scenarios

Scenario	HTTP status	Code
The format of the supplied NINO field is not valid.	400 (Bad Request)	FORMAT_NINO
One or more values have been added with the incorrect format.	400 (Bad Request)	FORMAT_VALUE
An empty or non-matching body was submitted.	400 (Bad Request)	RULE_INCORRECT_OR_EMPTY_BODY_SUBMITTED
The format of the supplied Loss ID is not valid.	400 (Bad Request)	FORMAT_LOSS_ID
The client or agent is not authorised. This is because: the client is not subscribed to MTD, the agent is not subscribed to Agent Services, or the client has not authorised the agent to act on their behalf.	403 (Forbidden)	CLIENT_OR_AGENT_NOT_AUTHORISED
The type of claim is the same as a previous submission for this income source.	403 (Forbidden)	RULE_NO_CHANGE
The remote endpoint has indicated that no data can be found for the given loss ID.	404 (Not Found)	MATCHING_RESOURCE_NOT_FOUND

For error scenarios that are common across all APIs, and for error formats, see our reference guide.

Test data

Scenario simulations using Gov-Test-Scenario headers is only available in the sandbox environment.

Header Value (Gov-Test-Scenario)	Scenario
N/A - DEFAULT	Simulates success response where type of loss is Self-Employment.
CLASS_4	Simulates the scenario where type of loss is Self-Employment Class 4.
FOREIGN_PROPERTY	Simulates the scenario where type of loss is Foreign Property.
FOREIGN_PROPERTY_FHL_EEA	Simulates the scenario where type of loss is Foreign Property FHL EEA.
UK_PROPERTY_FHL	Simulates the scenario where type of loss is UK Property FHL.
UK_PROPERTY_NON_FHL	Simulates the scenario where type of loss is UK Property Non-FHL.
NOT_FOUND	Simulates the scenario where no data is found.
NO_CHANGE	Simulates the scenario where the brought forward loss amount has not changed.

Close Section

Loss Claims

Resources related to a customer’s financial data for their loss claims.

Loss Claims resources

/individuals/losses/{nino}/loss-claims

List Loss Claims

GET

This endpoint allows a developer to retrieve the existing loss claims information. A National Insurance Number must be provided.

Authorisation

This endpoint is user-restricted and requires an Authorization header containing an OAuth 2.0 Bearer Token with the read:self-assessment scope.

Path parameters

Name	Description
nino string required	National Insurance number, in the format AA999999A. For example: TC663795B

Query parameters

Name	Description
taxYearClaimedFor string optional	The tax year to which the claim applies. The start year and end year must not span two tax years. The minimum tax year is 2019-20. No gaps are allowed, for example, 2022-24 is not valid. For example: 2022-23
businessId string optional	The unique identifier of the income source the claim relates to. Must conform to the regular expression ^X[A-Z0-9]{1}IS[0-9]{11}$ For example: XPIS00000001319
typeOfLoss string optional	The type of business the loss applies to. Limited to the following possible values: self-employment uk-property-non-fhl foreign-property
typeOfClaim string optional	The type of claim to be applied. Permitted values: carry-sideways

Request headers

Name	Description
Accept required	Specifies the response format and the version of the API to be used. For example: application/vnd.hmrc.3.0+json
Gov-Test-Scenario optional	Only in sandbox environment. See Test Data table for all header values. For example: -
Authorization required	An OAuth 2.0 Bearer Token with the read:self-assessment scope. For example: Bearer bb7fed3fe10dd235a2ccda3d50fb

See also fraud prevention.

Responses

HTTP status 200 (OK)

Response headers

Name	Description
X-CorrelationId required	Unique ID for operation tracking String, 36 characters. For example: c75f40a6-a3df-4429-a697-471eeec46435

See also fraud prevention.

Self-Employment Loss Claim

{
  "claims": [
    {
      "businessId": "XBIS12356589871",
      "typeOfLoss": "self-employment",
      "typeOfClaim": "carry-sideways",
      "taxYearClaimedFor": "2019-20",
      "claimId": "AAZZ0123456789a",
      "sequence": 1,
      "lastModified": "2020-07-13T12:13:48.763Z"
    }
  ],
  "links": [
    {
      "href": "/individuals/losses/TC663795B/loss-claims",
      "rel": "create-loss-claim",
      "method": "POST"
    },
    {
      "href": "/individuals/losses/TC663795B/loss-claims",
      "rel": "self",
      "method": "GET"
    }
  ]
}

UK Property Loss Claim

{
  "claims": [
    {
      "businessId": "XPIS12356589871",
      "typeOfLoss": "uk-property-non-fhl",
      "typeOfClaim": "carry-sideways",
      "taxYearClaimedFor": "2019-20",
      "claimId": "AAZZ0123456789a",
      "sequence": 1,
      "lastModified": "2020-07-13T12:13:48.763Z"
    }
  ],
  "links": [
    {
      "href": "/individuals/losses/TC663795B/loss-claims",
      "rel": "create-loss-claim",
      "method": "POST"
    },
    {
      "href": "/individuals/losses/TC663795B/loss-claims",
      "rel": "self",
      "method": "GET"
    }
  ]
}

Foreign Property Loss Claim

{
  "claims": [
    {
      "businessId": "XFIS12356589871",
      "typeOfLoss": "foreign-property",
      "typeOfClaim": "carry-sideways",
      "taxYearClaimedFor": "2019-20",
      "claimId": "AAZZ0123456789a",
      "sequence": 1,
      "lastModified": "2020-07-13T12:13:48.763Z"
    }
  ],
  "links": [
    {
      "href": "/individuals/losses/TC663795B/loss-claims",
      "rel": "create-loss-claim",
      "method": "POST"
    },
    {
      "href": "/individuals/losses/TC663795B/loss-claims",
      "rel": "self",
      "method": "GET"
    }
  ]
}

Name	Description
claims array required	An array of loss claim objects. An empty array is not returned, if no loss claims exist for the supplied NINO, a MATCHING_RESOURCE_NOT_FOUND error is returned.
businessId string required	An identifier for the business, unique to the customer. Must conform to the regular expression ^X[A-Z0-9]{1}IS[0-9]{11}$ For example: XAIS12345678910
typeOfLoss string required	The type of business the loss applies to. Limited to the following possible values: self-employment uk-property-non-fhl foreign-property
typeOfClaim string required	The type of claim to be applied. Permitted values for "self-employment": carry-forward, carry-sideways. Permitted values for "uk-property-non-fhl" and "foreign-property": carry-sideways, carry-sideways-fhl, carry-forward-to-carry-sideways. Limited to the following possible values: carry-forward carry-sideways carry-sideways-fhl carry-forward-to-carry-sideways
taxYearClaimedFor string required	The tax year to which the claim applies. The start year and end year must not span two tax years. The minimum tax year is 2019-20. No gaps are allowed, for example, 2022-24 is not valid. For example: 2022-23
claimId string required	Unique identifier for the loss claim. For example: AAZZ0123456789a
sequence number optional	The order number in which this loss claim is to be used it must be an integer in the range 1 to 99. The sequence must start with 1 and have no gaps.
lastModified string required	The timestamp when the entry was created or last modified. For example: 2020-07-13T12:13:48.763Z
links array optional	A list of endpoint links that indicate possible actions related to the current resource
href string required	The relative url of the endpoint For example: /individuals/losses/{nino}/loss-claims/{claimId}
rel string required	A label for the endpoint, which describes how it is related to the current resource The rel will be `self` where the action is retrieval of the same resource Limited to the following possible values: self
method string required	The HTTP method type for the endpoint Limited to the following possible values: GET
links array optional	A list of endpoint links that indicate possible actions related to the current resource
href string required	The relative url of the endpoint For example: /individuals/losses/{nino}/loss-claims
rel string required	A label for the endpoint, which describes how it is related to the current resource The rel will be self where the action is retrieval of the same resource Limited to the following possible values: self create-loss-claim amend-loss-claim-order
method string required	The HTTP method type for the endpoint Limited to the following possible values: GET POST PUT

Error scenarios

Scenario	HTTP status	Code
The format of the supplied NINO field is not valid.	400 (Bad Request)	FORMAT_NINO
The format of the supplied tax year field is not valid.	400 (Bad Request)	FORMAT_TAX_YEAR
The specified tax year is not supported. That is, the tax year specified is before the minimum tax year value.	400 (Bad Request)	RULE_TAX_YEAR_NOT_SUPPORTED
Tax year range invalid. A tax year range of one year is required.	400 (Bad Request)	RULE_TAX_YEAR_RANGE_INVALID
The format of the type of claim is not valid.	400 (Bad Request)	FORMAT_TYPE_OF_CLAIM
The format of the supplied type of loss field is not valid.	400 (Bad Request)	FORMAT_TYPE_OF_LOSS
The format of the supplied Business ID field is not valid.	400 (Bad Request)	FORMAT_BUSINESS_ID
The client or agent is not authorised. This is because: the client is not subscribed to MTD, the agent is not subscribed to Agent Services, or the client has not authorised the agent to act on their behalf.	403 (Forbidden)	CLIENT_OR_AGENT_NOT_AUTHORISED
Matching resource not found.	404 (Not Found)	MATCHING_RESOURCE_NOT_FOUND

For error scenarios that are common across all APIs, and for error formats, see our reference guide.

Test data

Scenario simulations using Gov-Test-Scenario headers is only available in the sandbox environment.

Header Value (Gov-Test-Scenario)	Scenario
N/A - DEFAULT	Simulates successful self-employment response where typeOfClaim is "carry-forward".
UK_PROPERTY	Simulates successful uk-property-non-fhl response where typeOfClaim is "carry-sideways-fhl".
FOREIGN_PROPERTY	Simulates successful foreign property response where typeOfClaim is "carry-sideways".
NOT_FOUND	Simulates the scenario where no data is found.

Close Section

/individuals/losses/{nino}/loss-claims

Create a Loss Claim

POST

This endpoint allows a developer to create a Loss Claim against an income source for a specific tax year. Claims cannot be made until after the End of Period Statement. A National Insurance number must be provided.

Authorisation

This endpoint is user-restricted and requires an Authorization header containing an OAuth 2.0 Bearer Token with the write:self-assessment scope.

Path parameters

Name	Description
nino string required	National Insurance number, in the format AA999999A. For example: TC663795B

Request headers

Name	Description
Accept required	Specifies the response format and the version of the API to be used. For example: application/vnd.hmrc.3.0+json
Content-Type required	Specifies the format of the request body, which must be JSON. For example: application/json
Gov-Test-Scenario optional	Only in sandbox environment. See Test Data table for all header values. For example: -
Authorization required	An OAuth 2.0 Bearer Token with the write:self-assessment scope. For example: Bearer bb7fed3fe10dd235a2ccda3d50fb

See also fraud prevention.

Request

Scenario: Self-Employment Claim Request

{
  "businessId": "XBIS12356589871",
  "typeOfLoss": "self-employment",
  "typeOfClaim": "carry-forward",
  "taxYearClaimedFor": "2019-20"
}

Scenario: UK Property Claim Request

{
  "businessId": "XPIS12356589871",
  "typeOfLoss": "uk-property-non-fhl",
  "typeOfClaim": "carry-sideways",
  "taxYearClaimedFor": "2019-20"
}

Scenario: Foreign Property Claim Request

{
  "businessId": "XFIS12356589871",
  "typeOfLoss": "foreign-property",
  "typeOfClaim": "carry-sideways",
  "taxYearClaimedFor": "2019-20"
}

Name	Description
taxYearClaimedFor string required	The tax year to which the claim applies. The start year and end year must not span two tax years. The minimum tax year is 2019-20. No gaps are allowed, for example, 2022-24 is not valid. For example: 2022-23
typeOfLoss string required	The type of business the loss applies to. Limited to the following possible values: self-employment uk-property-non-fhl foreign-property
typeOfClaim string required	The type of claim to be applied. Permitted values for "self-employment": carry-forward, carry-sideways. Permitted values for "uk-property-non-fhl" and "foreign-property": carry-sideways, carry-sideways-fhl, carry-forward-to-carry-sideways. Limited to the following possible values: carry-forward carry-sideways carry-sideways-fhl carry-forward-to-carry-sideways
businessId string required	An identifier for the business, unique to the customer. Must conform to the regular expression ^X[A-Z0-9]{1}IS[0-9]{11}$ For example: XAIS12345678910

Responses

HTTP status 201 (Created)

Response headers

Name	Description
X-CorrelationId required	Unique ID for operation tracking String, 36 characters. For example: c75f40a6-a3df-4429-a697-471eeec46435

See also fraud prevention.

{
  "claimId": "AAZZ1234567890A",
  "links": [
    {
      "href": "/individuals/losses/TC663795B/loss-claims/AAZZ1234567890A",
      "rel": "self",
      "method": "GET"
    },
    {
      "href": "/individuals/losses/TC663795B/loss-claims/AAZZ1234567890A/change-type-of-claim",
      "rel": "amend-loss-claim",
      "method": "POST"
    },
    {
      "href": "/individuals/losses/TC663795B/loss-claims/AAZZ1234567890A",
      "rel": "delete-loss-claim",
      "method": "DELETE"
    }
  ]
} 

Name	Description
claimId string required	An identifier for the newly created loss claim. Must conform to the regular expression ^[A-Za-z0-9]{15}$ For example: 1234568790ABCDE
links array optional	A list of endpoint links that indicate possible actions related to the current resource.
href string required	The relative url of the endpoint. For example: /individuals/losses/TC663795B/loss-claims/AAZZ1234567890A",
rel string required	A label for the endpoint, which describes how it is related to the current resource. The rel will be self where the action is retrieval of the same resource. Limited to the following possible values: self amend-loss-claim delete-loss-claim
method string required	The HTTP method type for the endpoint. Limited to the following possible values: GET POST DELETE

Error scenarios

Scenario	HTTP status	Code
The format of the supplied NINO field is not valid.	400 (Bad Request)	FORMAT_NINO
The format of the supplied taxYearClaimedFor value is not valid.	400 (Bad Request)	FORMAT_TAX_YEAR
The specified tax year is not supported. That is, the tax year specified is before the minimum tax year value.	400 (Bad Request)	RULE_TAX_YEAR_NOT_SUPPORTED
Tax year range invalid. A tax year range of one year is required.	400 (Bad Request)	RULE_TAX_YEAR_RANGE_INVALID
The format of the supplied type of loss field is not valid.	400 (Bad Request)	FORMAT_TYPE_OF_LOSS
The format of the type of claim is not valid.	400 (Bad Request)	FORMAT_TYPE_OF_CLAIM
The format of the supplied Business ID field is not valid.	400 (Bad Request)	FORMAT_BUSINESS_ID
The type of claim supplied is not valid.	400 (Bad Request)	RULE_TYPE_OF_CLAIM_INVALID
An empty or non-matching body was submitted.	400 (Bad Request)	RULE_INCORRECT_OR_EMPTY_BODY_SUBMITTED
The type of claim is the same as a previous submission for this income source.	403 (Forbidden)	RULE_DUPLICATE_SUBMISSION
The accounting period has not yet ended.	403 (Forbidden)	RULE_ACCOUNTING_PERIOD_NOT_ENDED
There is no accounting period for the year of the claim.	403 (Forbidden)	RULE_NO_ACCOUNTING_PERIOD
The client or agent is not authorised. This is because: the client is not subscribed to MTD, the agent is not subscribed to Agent Services, or the client has not authorised the agent to act on their behalf.	403 (Forbidden)	CLIENT_OR_AGENT_NOT_AUTHORISED
The supplied income source could not be found.	404 (Not Found)	MATCHING_RESOURCE_NOT_FOUND

For error scenarios that are common across all APIs, and for error formats, see our reference guide.

Test data

Scenario simulations using Gov-Test-Scenario headers is only available in the sandbox environment.

Header Value (Gov-Test-Scenario)	Scenario
N/A - DEFAULT	Simulates success response.
NOT_FOUND	Simulates the scenario where no data is found.
DUPLICATE	Simulates the scenario where a duplicated value is found.
ACCOUNTING_PERIOD_NOT_ENDED	Simulates the scenario where the Loss claim has been made too soon.
NO_ACCOUNTING_PERIOD	Simulates the scenario where there is no accounting period for the year of the claim.

Close Section

/individuals/losses/{nino}/loss-claims/{claimId}

Retrieve a Loss Claim

GET

This endpoint allows a developer to retrieve the detail of an existing loss claim. A National Insurance Number and Claim ID must be provided.

Authorisation

This endpoint is user-restricted and requires an Authorization header containing an OAuth 2.0 Bearer Token with the read:self-assessment scope.

Path parameters

Name	Description
nino string required	National Insurance number, in the format AA999999A. For example: TC663795B
claimId string required	Unique identifier for the loss claim. Must conform to the regular expression ^[A-Za-z0-9]{15}$ For example: AAZZ0123456789a

Request headers

Name	Description
Accept required	Specifies the response format and the version of the API to be used. For example: application/vnd.hmrc.3.0+json
Gov-Test-Scenario optional	Only in sandbox environment. See Test Data table for all header values. For example: -
Authorization required	An OAuth 2.0 Bearer Token with the read:self-assessment scope. For example: Bearer bb7fed3fe10dd235a2ccda3d50fb

See also fraud prevention.

Responses

HTTP status 200 (OK)

Response headers

Name	Description
X-CorrelationId required	Unique ID for operation tracking String, 36 characters. For example: c75f40a6-a3df-4429-a697-471eeec46435

See also fraud prevention.

Self-Employment Loss Claim

{
  "taxYearClaimedFor": "2021-22",
  "typeOfLoss": "self-employment",
  "typeOfClaim": "carry-sideways",
  "businessId": "XBIS12356589871",
  "sequence": 1,
  "lastModified": "2022-07-13T12:13:48.763Z"
}

UK Property Loss Claim

{
  "taxYearClaimedFor": "2021-22",
  "typeOfLoss": "uk-property-non-fhl",
  "typeOfClaim": "carry-sideways",
  "businessId": "XPIS12356589871",
  "sequence": 1,
  "lastModified": "2022-07-13T12:13:48.763Z"
}

Foreign Property Claim

{
  "taxYearClaimedFor": "2021-22",
  "typeOfLoss": "foreign-property",
  "typeOfClaim": "carry-sideways",
  "businessId": "XFIS12356589871",
  "sequence": 1,
  "lastModified": "2022-07-13T12:13:48.763Z"
}

Name	Description
taxYearClaimedFor string required	The tax year to which the claim applies. The start year and end year must not span two tax years. The minimum tax year is 2019-20. No gaps are allowed, for example, 2022-24 is not valid. For example: 2022-23
typeOfLoss string required	The type of business the loss applies to. Limited to the following possible values: self-employment uk-property-non-fhl foreign-property
typeOfClaim string required	The type of claim to be applied. Permitted values for "self-employment": carry-forward, carry-sideways. Permitted values for "uk-property-non-fhl" and "foreign-property": carry-sideways, carry-sideways-fhl, carry-forward-to-carry-sideways. Limited to the following possible values: carry-forward carry-sideways carry-sideways-fhl carry-forward-to-carry-sideways
businessId string required	An identifier for the business, unique to the customer. Must conform to the regular expression ^X[A-Z0-9]{1}IS[0-9]{11}$ For example: XAIS12345678910
sequence number optional	The order number in which this loss claim is to be used it must be an integer in the range 1 to 99. The sequence must start with 1 and have no gaps.
lastModified string required	The timestamp when the entry was created or last modified. For example: 2020-07-13T12:13:48.763Z
links array optional	A list of endpoint links that indicate possible actions related to the current resource.
href string required	The relative url of the endpoint. For example: /individuals/losses/TC663795B/loss-claims/AAZZ0123456789a
rel string required	A label for the endpoint, which describes how it is related to the current resource. The rel will be self where the action is retrieval of the same resource. Limited to the following possible values: self
method string required	The HTTP method type for the endpoint. Limited to the following possible values: GET

Error scenarios

Scenario	HTTP status	Code
The format of the supplied NINO field is not valid.	400 (Bad Request)	FORMAT_NINO
The format of the supplied Claim ID is not valid.	400 (Bad Request)	FORMAT_CLAIM_ID
The client or agent is not authorised. This is because: the client is not subscribed to MTD, the agent is not subscribed to Agent Services, or the client has not authorised the agent to act on their behalf.	403 (Forbidden)	CLIENT_OR_AGENT_NOT_AUTHORISED
One or more loss claims not be found on this account.	404 (Not Found)	MATCHING_RESOURCE_NOT_FOUND

For error scenarios that are common across all APIs, and for error formats, see our reference guide.

Test data

Scenario simulations using Gov-Test-Scenario headers is only available in the sandbox environment.

Header Value (Gov-Test-Scenario)	Scenario
N/A - DEFAULT	Simulates successful self-employment response where typeOfClaim is "carry-forward".
UK_PROPERTY	Simulates successful uk-property-non-fhl response where typeOfClaim is "carry-sideways-fhl".
FOREIGN_PROPERTY	Simulates successful foreign-property response where typeOfClaim is "carry-sideways".
NOT_FOUND	Simulates the scenario where no data is found.

Close Section

/individuals/losses/{nino}/loss-claims/{claimId}

Delete a Loss Claim

DELETE

This endpoint allows a developer to delete an existing Loss Claim. A National Insurance number and Claim ID must be provided.

Authorisation

This endpoint is user-restricted and requires an Authorization header containing an OAuth 2.0 Bearer Token with the write:self-assessment scope.

Path parameters

Name	Description
nino string required	National Insurance number, in the format AA999999A. For example: TC663795B
claimId string required	Unique identifier for the loss claim. Must conform to the regular expression ^[A-Za-z0-9]{15}$ For example: AAZZ0123456789a

Request headers

Name	Description
Accept required	Specifies the response format and the version of the API to be used. For example: application/vnd.hmrc.3.0+json
Content-Type required	Specifies the format of the request body, which must be JSON. For example: application/json
Gov-Test-Scenario optional	Only in sandbox environment. See Test Data table for all header values. For example: -
Authorization required	An OAuth 2.0 Bearer Token with the write:self-assessment scope. For example: Bearer bb7fed3fe10dd235a2ccda3d50fb

See also fraud prevention.

Responses

HTTP status 204 (No Content)

Response headers

Name	Description
X-CorrelationId required	Unique ID for operation tracking String, 36 characters. For example: c75f40a6-a3df-4429-a697-471eeec46435

See also fraud prevention.

Error scenarios

Scenario	HTTP status	Code
The format of the supplied NINO field is not valid.	400 (Bad Request)	FORMAT_NINO
The format of the supplied Claim ID is not valid.	400 (Bad Request)	FORMAT_CLAIM_ID
The client or agent is not authorised. This is because: the client is not subscribed to MTD, the agent is not subscribed to Agent Services, or the client has not authorised the agent to act on their behalf.	403 (Forbidden)	CLIENT_OR_AGENT_NOT_AUTHORISED
One or more loss claims not be found on this account.	404 (Not Found)	MATCHING_RESOURCE_NOT_FOUND

For error scenarios that are common across all APIs, and for error formats, see our reference guide.

Test data

Scenario simulations using Gov-Test-Scenario headers is only available in the sandbox environment.

Header Value (Gov-Test-Scenario)	Scenario
N/A - DEFAULT	Simulate success scenario
NOT_FOUND	Simulates the scenario where no data is found.

Close Section

/individuals/losses/{nino}/loss-claims/{claimId}/change-type-of-claim

Amend a Loss Claim Type

POST

This endpoint allows a developer to change the type of claim for an existing loss claim type. A National Insurance Number and Claim ID must be provided.

Authorisation

This endpoint is user-restricted and requires an Authorization header containing an OAuth 2.0 Bearer Token with the read:self-assessment scope.

Path parameters

Name	Description
nino string required	National Insurance number, in the format AA999999A. For example: TC663795B
claimId string required	Unique identifier for the loss claim. Must conform to the regular expression ^[A-Za-z0-9]{15}$ For example: AAZZ0123456789a

Request headers

Name	Description
Accept required	Specifies the response format and the version of the API to be used. For example: application/vnd.hmrc.3.0+json
Gov-Test-Scenario optional	Only in sandbox environment. See Test Data table for all header values. For example: -
Authorization required	An OAuth 2.0 Bearer Token with the read:self-assessment scope. For example: Bearer bb7fed3fe10dd235a2ccda3d50fb

See also fraud prevention.

Request

{
  "typeOfClaim": "carry-forward"
}

Name	Description
typeOfClaim string required	The type of claim to be applied. Permitted values for "self-employment": carry-forward, carry-sideways. Permitted values for "uk-property-non-fhl" and "foreign-property": carry-sideways, carry-sideways-fhl, carry-forward-to-carry-sideways. For example: carry-forward

Responses

HTTP status 200 (OK)

Response headers

Name	Description
X-CorrelationId required	Unique ID for operation tracking String, 36 characters. For example: c75f40a6-a3df-4429-a697-471eeec46435

See also fraud prevention.

{
  "typeOfLoss": "self-employment",
  "businessId": "X2IS12356589871",
  "typeOfClaim": "carry-forward",
  "taxYearClaimedFor": "2019-20",
  "sequence": 2,
  "lastModified": "2020-07-13T12:13:48.763Z"
}

Name	Description
taxYearClaimedFor string required	The tax year to which the claim applies. The start year and end year must not span two tax years. The minimum tax year is 2019-20. No gaps are allowed, for example, 2022-24 is not valid. For example: 2022-23
typeOfLoss string required	The type of business the loss applies to. Limited to the following possible values: self-employment uk-property-non-fhl foreign-property Limited to the following possible values: self-employment uk-property-non-fhl foreign-property
typeOfClaim string required	The type of claim to be applied. Permitted values for "self-employment": carry-forward carry-sideways Permitted values for "uk-property-non-fhl" and "foreign-property": carry-sideways carry-sideways-fhl carry-forward-to-carry-sideways Limited to the following possible values: carry-forward carry-sideways carry-sideways-fhl carry-forward-to-carry-sideways
businessId string required	An identifier for the business, unique to the customer. Must conform to the regular expression ^X[A-Z0-9]{1}IS[0-9]{11}$ For example: XAIS12345678910
sequence number optional	The order number in which this loss claim is to be used it must be an integer in the range 1 to 99. The sequence must start with 1 and have no gaps.
lastModified string required	The timestamp when the entry was created or last modified. For example: 2020-07-13T12:13:48.763Z
links array optional	A list of endpoint links that indicate possible actions related to the current resource.
href string required	The relative url of the endpoint. For example: /individuals/losses/TC663795B/loss-claims/AAZZ0123456789a
rel string required	A label for the endpoint, which describes how it is related to the current resource. The rel will be self where the action is retrieval of the same resource. Limited to the following possible values: self
method string required	The HTTP method type for the endpoint. Limited to the following possible values: GET

Error scenarios

Scenario	HTTP status	Code
The format of the supplied NINO field is not valid.	400 (Bad Request)	FORMAT_NINO
The format of the supplied Claim ID is not valid.	400 (Bad Request)	FORMAT_CLAIM_ID
One or more values have been added with the incorrect format.	400 (Bad Request)	FORMAT_VALUE
The format of the type of claim is not valid.	400 (Bad Request)	FORMAT_TYPE_OF_CLAIM
The type of claim supplied is not valid.	400 (Bad Request)	RULE_TYPE_OF_CLAIM_INVALID
An empty or non-matching body was submitted.	400 (Bad Request)	RULE_INCORRECT_OR_EMPTY_BODY_SUBMITTED
The type of claim is the same as a previous submission for this income source.	403 (Forbidden)	RULE_NO_CHANGE
The client or agent is not authorised. This is because: the client is not subscribed to MTD, the agent is not subscribed to Agent Services, or the client has not authorised the agent to act on their behalf.	403 (Forbidden)	CLIENT_OR_AGENT_NOT_AUTHORISED
One or more loss claims not be found on this account.	404 (Not Found)	MATCHING_RESOURCE_NOT_FOUND

For error scenarios that are common across all APIs, and for error formats, see our reference guide.

Test data

Scenario simulations using Gov-Test-Scenario headers is only available in the sandbox environment.

Header Value (Gov-Test-Scenario)	Scenario
N/A - DEFAULT	Simulates success response.
FP_FORWARD	Simulates a Foreign Property carried forward scenario.
FP_SIDEWAYS	Simulates a Foreign Property carried sideways scenario.
NONFHL_FORWARD	Simulates a Non-FHL carried forward scenario.
NONFHL_FORWARD_TO_SIDEWAYS	Simulates a Non-FHL carried forward to sideways scenario.
NONFHL_SIDEWAYS	Simulates a Non-FHL carried sideways scenario.
NONFHL_SIDEWAYS_FHL	Simulates a FHL carried sideways scenario.
SE_FORWARD	Simulates a Self Employment carried forward scenario.
SE_SIDEWAYS	Simulates a Self Employment carried sideways scenario.
NO_CHANGE	Simulates the scenario where the relief type has not changed.
TYPE_OF_CLAIM_INVALID	Simulates the scenario where a claim type is invalid for the income source.
NOT_FOUND	Simulates the scenario where no data is found.

Close Section

/individuals/losses/{nino}/loss-claims/order/{taxYearClaimedFor}

Amend Loss Claims Order

PUT

This endpoint allows the developer to change the sequence in which certain losses are used. A National Insurance Number must be provided.

Authorisation

This endpoint is user-restricted and requires an Authorization header containing an OAuth 2.0 Bearer Token with the write:self-assessment scope.

Path parameters

Name	Description
nino string required	National Insurance number, in the format AA999999A. For example: TC663795B
taxYearClaimedFor string required	The tax year to which the claim applies. The start year and end year must not span two tax years. The minimum tax year is 2019-20. No gaps are allowed, for example, 2022-24 is not valid. For example: 2022-23

Request headers

Name	Description
Accept required	Specifies the response format and the version of the API to be used. For example: application/vnd.hmrc.3.0+json
Content-Type required	Specifies the format of the request body, which must be JSON. For example: application/json
Gov-Test-Scenario optional	Only in sandbox environment. See Test Data table for all header values. For example: -
Authorization required	An OAuth 2.0 Bearer Token with the write:self-assessment scope. For example: Bearer bb7fed3fe10dd235a2ccda3d50fb

See also fraud prevention.

Request

{
  "typeOfClaim": "carry-sideways",
  "listOfLossClaims": [
    {
      "claimId": "1234567890ABCDE",
      "sequence": 2
    },
    {
      "claimId": "1234567890ABDE0",
      "sequence": 3
    },
    {
      "claimId": "1234567890ABEF1",
      "sequence": 1
    }
  ]
}

Name	Description
typeOfClaim string required	The type of loss claims whose order is to be amended. Limited to the following possible values: carry-sideways
listOfLossClaims array required	A list of the claims to be amended - all of the claims for a given type and tax year must be included in the submission.
claimId string required	The unique identifier for the loss claim. Must conform to the regular expression ^[A-Za-z0-9]{15} For example: 1234568790ABCDE
sequence integer required	The order number in which this loss claim is to be used. It must be an integer in the range 1 to 99. The sequence must start with 1 and have no gaps. For example: 1

Responses

HTTP status 200 (OK)

Response headers

Name	Description
X-CorrelationId required	Unique ID for operation tracking String, 36 characters. For example: c75f40a6-a3df-4429-a697-471eeec46435

See also fraud prevention.

{
  "links": [
    {
      "href": "/individuals/losses/TC663795B/loss-claims/order/2022-23",
      "rel": "self",
      "method": "PUT"
    },
    {
      "href": "/individuals/losses/TC663795B/loss-claims",
      "rel": "list-loss-claims",
      "method": "GET"
    }
  ]
}

Name	Description
links array optional	A list of endpoint links that indicate possible actions related to the current resource.
href string required	The relative url of the endpoint For example: /individuals/losses/TC663795B/loss-claims/order/2022-23
rel string required	A label for the endpoint, which describes how it is related to the current resource. The rel will be self where the action is retrieval of the same resource. Limited to the following possible values: self list-loss-claims
method string required	The HTTP method type for the endpoint. Limited to the following possible values: PUT GET

Error scenarios

Scenario	HTTP status	Code
The format of the supplied NINO field is not valid.	400 (Bad Request)	FORMAT_NINO
The format of the supplied tax year field is not valid.	400 (Bad Request)	FORMAT_TAX_YEAR
The format of the supplied Claim ID is not valid.	400 (Bad Request)	FORMAT_CLAIM_ID
The format of the supplied claim type is not valid.	400 (Bad Request)	FORMAT_TYPE_OF_CLAIM
The format of the supplied sequence number is not valid.	400 (Bad Request)	FORMAT_SEQUENCE
The sequence does not begin with 1.	400 (Bad Request)	RULE_INVALID_SEQUENCE_START
The sequence is not continuous.	400 (Bad Request)	RULE_SEQUENCE_ORDER_BROKEN
Not all of the loss claims of this type for this tax year were included in the submission.	400 (Bad Request)	RULE_LOSS_CLAIMS_MISSING
An empty or non-matching body was submitted.	400 (Bad Request)	RULE_INCORRECT_OR_EMPTY_BODY_SUBMITTED
The specified tax year is not supported. That is, the tax year specified is before the minimum tax year value.	400 (Bad Request)	RULE_TAX_YEAR_NOT_SUPPORTED
Tax year range invalid. A tax year range of one year is required.	400 (Bad Request)	RULE_TAX_YEAR_RANGE_INVALID
The client or agent is not authorised. This is because: the client is not subscribed to MTD, the agent is not subscribed to Agent Services, or the client has not authorised the agent to act on their behalf.	403 (Forbidden)	CLIENT_OR_AGENT_NOT_AUTHORISED
One or more loss claims not be found on this account.	404 (Not Found)	MATCHING_RESOURCE_NOT_FOUND

For error scenarios that are common across all APIs, and for error formats, see our reference guide.

Test data

Scenario simulations using Gov-Test-Scenario headers is only available in the sandbox environment.

Header Value (Gov-Test-Scenario)	Scenario
N/A - DEFAULT	Simulates success response.
LOSS_CLAIMS_MISSING	Simulates the scenario where one of more claims were not found.
NOT_FOUND	Simulates the scenario where not all claims of the given type and year were included.

Close Section

Skip to main content

Is this page not working properly? (opens in new tab)