email_verification_required
The account exists and authenticated, but has not proved its email address, which onboarding requires before it can be started or paid for. Cure is the verification link, or POST /v1/auth/email-verifications for another one - not a different request.
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/email_verification_required",
"title": "…",
"status": 403,
"detail": "…",
"instance": "/v1/…"
}