Testing the Partner Filing API
- Latest version
- Version 1.2.0 Beta
- Last updated
- 10 November 2026
- API type
- REST
- Sandbox base URL
- Provided with sandbox access
- Production base URL
https://www.simplecompanytax.co.uk/api/v1
Developer documentation
Testing
Each published example runs through the shared save builder and real document generation in the contract test suite. Long periods include enter-once and separate company figures. The sandbox company catalogue below lists each test company and its outcome.
| Sandbox company number | Company | Outcome |
|---|---|---|
00000001 | Private limited company, England and Wales | Accepted |
00000002 | Private limited company, England and Wales | Rejected |
00000003 | Private limited company, England and Wales | Authentication failure |
00000005 | Private limited company, England and Wales | Unknown outcome |
00000006 | Private limited company, England and Wales | First return accepted, second return rejected |
00000007 | Community interest company, England and Wales | Accepted |
00000008 | Company limited by guarantee, England and Wales | Accepted |
SC000001 | Private limited company, Scotland | Accepted |
NI000001 | Private limited company, Northern Ireland | Accepted |
Real sandbox dry-run request and response examples cover both long-period entry modes. They are captured from authenticated HTTP, disposable database admission, the worker and the filing read endpoint. In a dry run, complete describes prepared documents. It does not mean an authority has accepted the pending filing parts.
Download all complete request examples, including each exercised filing choice. Read the complete examples.