Marriage Allowance API
| REST | |
| Version 2.0 - beta | |
| 28 April 2026 | |
| Sandbox base URL | https://test-api.service.hmrc.gov.uk |
| Production base URL | https://api.service.hmrc.gov.uk |
Overview
This API provides resources related to Marriage Allowance.
Marriage Allowance lets the lower earner of a couple transfer some of their Personal Allowance to their husband, wife or civil partner. If they are eligible this will then lower their tax bill.
In particular, this API can
- Retrieve an individual’s Marriage Allowance status
- Check their partner’s eligibility to be a recipient of Marriage Allowance (useful if the individual is considering applying for Marriage Allowance)
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.
Testing
You can use the sandbox environment to test this API.
It supports stateful behaviour. You can set up test data for this API using the Marriage Allowance Test Support API.
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.
Endpoints
| Version | Environments | Endpoints |
|---|---|---|
|
Version 2.0 - beta
(opens in new tab) |
Sandbox and Production | 2.0 endpoints |