Automatic SMS & MMS Fallback for RCS

3, Jul 2025

We’ve added SMS & MMS fallback support for RCS messages in the Telnyx Messaging API. When RCS isn’t available on the recipient’s device or carrier, your message will still be delivered via the fallback channel you define.

How will this help Telnyx users

Reliability is king in messaging. This feature ensures your RCS-first campaigns don’t hit dead ends, you maintain full coverage without manually rerouting traffic.

How it works

Add fallback objects to your RCS send request:

"sms_fallback": { "sms_fallback": { "from": "+13125551234", "text": "Hello world!" }, "mms_fallback": { "from": "+13125551234", "subject": "Test Message", "media_urls": ["http://example.com/some_media.jpg"], "text": "Hello world!" }

Getting started

Start improving the reliability and coverage of your RCS workflows via our API.