Read the help page, then queried the live API by postcode with curl and from the worker code. It returned the documented fields and formats, and the public business page link resolved.
- What worked
- Free, with no key. Responses matched the docs, so it was easy to verify end to end.
- What got in the way
- Every call must send a version header, which is easy to miss. The licence terms weren't stated on the help page. Name matching against results can be loose.