Upcoming cipher suite list update for all Twilio REST API endpoints on June 3, 2026

After June 3, we’ll move into a phased deprecation and this extra time will help make the switch as smooth as possible.

If customers are using legacy network software or older operating systems, they may need to update their systems to support the following new ciphers:

TLSv1.3_2025 ciphers

• TLS_AES_128_GCM_SHA256

• TLS_AES_256_GCM_SHA384

RSA ciphers (TLSv1.2_2025)

• ECDHE-RSA-AES128-GCM-SHA256

• ECDHE-RSA-AES256-GCM-SHA384

How to prepare for the new ciphers

• Run a test: Customers can check today whether their current setup is already compatible with the newer ciphers above. From their production environment, customers can make an unauthenticated request to https://tls-test.twilio.com using the same application stack that calls the Twilio API. If they get a 200 OK response, there are no changes needed. If the connection fails, their setup needs an upgrade (keep reading).
• Upgrade (if the test failed)
  • Direct API users: Verify OS and TLS library support TLS 1.2 or TLS 1.3 with the ciphers above. Customers should check with their OS and TLS library providers for compatibility details.
  • Helper Library users: Cipher negotiation is handled by the underlying runtime and OS, not the Helper Library. Customers should check their runtime and OS providers for TLS 1.2 or TLS 1.3 support. We also recommend upgrading to the latest Twilio Helper Library.
• Verify the connection: After upgrading, run the same test again. Once customers see that 200 OK response, they're all set.

Need a hand?

Check out these resources for more information:

• Monitoring Updates to Twilio REST API Security Settings
• Security | Twilio