vocapableworkspace_contact_phone_taken
Someone in this company already has that phone number (adding a person, or a customer with its first person). existing_contact_id names that person, and existing_organization_id the customer they are filed under, when you can open them; both are null when they are in a teammate's book.
Problem shape
Every non-2xx response is an RFC 9457 application/problem+json body. The type URI below is stable and machine-matchable, so branch on the final path segment (the code) and treat the status as redundant confirmation. See the error-handling guide.
{
"type": "https://docs.vocapable.com/errors/workspace_contact_phone_taken",
"title": "…",
"status": 409,
"detail": "…",
"instance": "/v1/…"
}