Phone System Error Codes
When a call or text fails, the system logs a specific error code that tells you exactly why — far more useful than "message failed." A few of the most common ones:
| Code | Meaning | What to do |
|---|---|---|
| 21211 | Invalid "To" number | The number isn't formatted correctly. Use full international format (+ + country code + number), and make sure you're not accidentally texting your own number. |
| 21610 | Recipient unsubscribed | The recipient previously replied STOP, or has messaging blocked. Don't message them again until they explicitly opt back in. |
| 30002 | Account suspended | Your account or number is suspended, usually for a compliance reason — see Why Your Phone System Access Was Suspended. |
| 30007 | Message filtered | A carrier flagged the message as likely spam, phishing, or fraud and blocked it. Review your content and A2P registration status — see Troubleshooting SMS Delivery. |
How to use this when something fails
- Note the exact error code shown in the message log or messaging analytics dashboard.
- Check what it means and its likely cause (many follow the pattern above — formatting issues, consent issues, account status, or content filtering).
- Fix the underlying issue — reformat the number, get fresh consent, resolve the account suspension, or adjust your message content.
- If the fix doesn't resolve it, contact support with the specific error code and a sample of the affected message — that's far faster to diagnose than "texting isn't working."
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