National Insurance API
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 retrieves an annual summary of an individual taxpayer's class 1 total earnings and class 2 National Insurance contributions due for a given tax year.
Its primary use is for the calculation of a self-employed taxpayer's National Insurance liability within the Self Assessment tax calculation.
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 National Insurance 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
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.