National Insurance Test Support API
|Version and status|
|Available in Sandbox||Yes|
|Sandbox base URL||https://test-api.service.hmrc.gov.uk|
|Available in Production||No|
Lets you set up test data for the National Insurance API.
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.
You can use the HMRC Developer Sandbox to test the API. The Sandbox is an enhanced testing service that functions as a simulator of HMRC’s production environment.
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.
The way we show National Insurance Test Support API v1.0 endpoints has changed, which might look different to other Developer Hub APIs.
The API has not changed. You do not need to make any updates to your application if you already use this API.