SUPPORT.TWILIO.COM END OF LIFE NOTICE: This site,, is scheduled to go End of Life on February 27, 2024. All Twilio Support content has been migrated to, where you can continue to find helpful Support articles, API docs, and Twilio blog content, and escalate your issues to our Support team. We encourage you to update your bookmarks and begin using the new site today for all your Twilio Support needs.

Verify Voice OTP to China Blocked

What is happening

Effective Monday, July 10, 2023, after 5PM PST, all Twilio Verify and Authy Voice (Call) API requests to China will be blocked with error code 21215 or similar. 

Why is it happening

Due to strict spam monitoring and regulations on communications terminating to China, short term duration calls of less than 3 minutes are not permitted. All of the OTP-containing phone calls that Verify/Authy API makes are less than 3 minutes, so they are no longer allowed. This is a universal behavior for all international traffic terminating to China, and is not something unique to Twilio’s platform.

How to manage the change

Consider switching to an alternative channel for sending OTPs to China, such as Verify SMS and Verify Email. For the full details on enabling Verify SMS, see Use Case Vetting for Verify Messages to China.

Please reach out to your Technical Account Manager or contact our Support team if you have any further questions.

Have more questions? Submit a request
Powered by Zendesk