Phone System · 1 min read
Error 30453: Blocked by Carrier as a Fraud Precaution
What this error means
Error 30453 means the recipient's carrier temporarily blocked SMS traffic to that destination because the pattern looked unusual or similar to known fraud. Legitimate messages are sometimes caught. The restriction often clears automatically if no more suspicious activity is detected.
Common triggers
- A sudden spike in messages to one destination.
- Unusual sending patterns, such as many messages in a short time.
- Traffic that resembles known fraud, such as repeated verification codes.
- Messages with suspicious links or URL shorteners.
How to fix it
- Stop sending to the affected number for a while.
- Review the content you sent. Remove shortened links and anything that looks like phishing.
- Check workflows for loops that might be sending the same message repeatedly.
- Resume at a normal pace once the restriction clears.
- If the error continues for legitimate traffic, contact support with the destination number and message details.
Prevention
Send at a steady pace, use full branded links, and add limits to workflows that send codes or alerts.