If your SMS shows failed or undeliverable, the cause is usually one of a few common issues. Here's how to diagnose and fix them.
Checklist
- Number format — use international E.164 (country code, no plus or leading zero as required).
- Sender ID — must be registered/approved for that country.
- Content — some operators block URLs or flagged keywords.
- Balance — ensure the bind has SMS credits.
- Route/IP — for SMPP, confirm your IP is whitelisted and the bind is bound.
Still stuck? Share the message ID with our support team and we'll trace the DLR.