Hi,
If a CRN number is incorrectly formatted in the Company Profile API call
GET https://api.company-information.service.gov.uk/company/{companyNumber}
What’s the response code.
You can try this yourself - just feed in e.g. 123456 as the company code (this is missing a couple of digits) or “XX123456” (right length but unknown prefix) - you’ll get a 404.
If you mangle the request enough you might get a 400 but I haven’t checked this.