30450: Message delivery blocked

Twilio blocked delivery to the destination number because SMS Pumping Protection identified the message request as suspicious. This block is temporary and helps reduce SMS pumping fraud.

• SMS Pumping Protection detected unusual traffic patterns for the destination number, region, country, or locale.
• The destination matched a pattern associated with known malicious activity or SMS pumping fraud.
• The destination number is still within a temporary block window, which is typically 15 to 30 minutes.
• Additional suspicious activity was detected after an earlier block, so the temporary block was extended or repeated.

• Wait for the temporary block window to expire, then retry the message. Delivery usually resumes after 15 to 30 minutes, but it can take longer if suspicious activity continues.
• Review the traffic pattern that triggered the block. Check whether your application is sending OTP, verification, or other high-volume traffic to destinations you do not normally message.
• Keep RiskCheck enabled for OTP or authentication traffic so SMS Pumping Protection can continue to protect those message flows.
• For legitimate traffic that should bypass this protection, create the Message resource with RiskCheck set to disable.
• Add known legitimate phone numbers or 1k prefixes to the Global Safe List so future messages to those destinations are not blocked by fraud checks.
• If legitimate traffic continues to be blocked, collect at least three recent Message SIDs that show This error and open a support request through the Console or Help Center.

• SMS Pumping Protection for Programmable Messaging
• Messages resource
• Global Safe List