credit_note_not_comped
The same route against an invoice whose tenant's commercial_status is not comped (nor an internal/trial arrangement that credits). A credit note against a paying tenant is a different accounting event - a service-fault credit, which is a WalletEntry under 11-billing.md §Refunds, credits, disputes - and this route refuses to be the path to it, because the two book to different accounts and make opposite statements about the customer. What an operator does: if the tenant should be comped, set the commercial status first (which itself gates on the collection method); if this is a service-fault remedy, use billing.credit.grant. P1 - built 2026-08-19 (billing_admin.py:1438, keyed on tenants.commercial_status from migration 0076).
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/credit_note_not_comped",
"title": "…",
"status": 422,
"detail": "…",
"instance": "/v1/…"
}