Self Assessment Accounts (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 a developer to retrieve the overall liability broken down into overdue, payable and pending amounts.
With this API the developer can:
- Retrieve History of a Self Assessment Charge
- Retrieve Self Assessment Balance and Transactions
- Retrieve History of a Self Assessment Charge
- Retrieve, Create or Amend, or Delete coding out amounts
For information on how to connect to this API see the Income Tax MTD end-to-end service guide.
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"
}
]
}
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.
Versioning
Endpoints
View API endpointsWhy do these endpoints look different?
The endpoints for this API now use the Open API Specification (OAS).
The API has not changed. You do not need to make any updates to your application if you already use this API.