This version is in beta - expect some breaking changes.

CIS Deductions (MTD) API

Available in Sandbox Yes
Sandbox base URL
Available in Production Yes
Production base URL


Under the Construction Industry Scheme (CIS), contractors deduct money from a subcontractor’s payments and pass it to HM Revenue and Customs (HMRC). The deductions count as advance payments towards the subcontractor’s tax and National Insurance.

This API allows the developer to:

  • retrieve details of the data the contractor has submitted to HMRC
  • retrieve a list of CIS deductions
  • create CIS deductions
  • remove CIS deductions
  • override previous CIS deductions (after the tax year has ended)

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


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"         }     ] }


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.


Some endpoints support DYNAMIC gov test scenarios. The response is dynamic based on the request parameters:

  • Retrieve CIS Deductions for Subcontractor V2.0


All the endpoints in version 2.0 support STATEFUL gov test scenarios. Stateful scenarios work with groups of endpoints that represent particular types of submissions. For each type you can POST (or PUT) to submit or amend data, GET to retrieve or list data and DELETE to delete data. For example, with a STATEFUL gov test scenario a retrieval will return data based on what you submitted.



View API endpoints
Why 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.