WhatsApp error 131016: Service unavailable

Code 131016 is a transient failure inside the WhatsApp messaging service. A component the send depended on was unavailable at that moment, and the request was not completed. No message ID is returned, so the message was not sent, and it is safe to retry without risk of a duplicate. Think of it as the WhatsApp-layer counterpart of Graph API code 2.

You will occasionally see a small trickle of 131016 on a healthy integration. That is normal and should be absorbed by retry logic. A sustained spike across all sends, especially when the WhatsApp Business Platform status page shows an incident, is a platform event and not something to debug in your code.

The code carries no information about your payload, token, template, or recipient. None of those need changing in response to it.

131016 can appear in the synchronous response or, more rarely, in a statuses webhook when a component fails after acceptance. If a spike coincides with code 2 or 131000, treat it as one incident rather than three separate bugs; the triage order is covered in the error-code guide.

Design sends to be durable and idempotent so a temporary unavailability costs a delay, not data. A circuit breaker that opens on consecutive 131016 responses and probes periodically keeps your queue orderly, and alerting on the error rate rather than single occurrences stops on-call from being paged for normal background noise.