Problems·HTTP 502

upstream-unavailable

The Peppol network could not be asked.

What it means

The SML, or the participant's SMP, did not answer. That is not the same as "not registered": a business that is not on Peppol gets a 200 with registered: false.

What to do

Retry after the Retry-After interval.

Example

Sent as application/problem+json (RFC 9457). Branch on type, which is stable. Never branch on title or detail, which are prose and may change.

{  "type": "https://www.einvoicing.dev/problems/upstream-unavailable",  "title": "The Peppol network could not be asked.",  "status": 502,  "detail": "…"}