> • Effective July 5, 2023, all 10DLC phone numbers used to send SMS and MMS messages to U.S. phone numbers must be fully registered to an approved campaign under your brand. Messages sent using unregistered phone numbers will be subject to a gradual increase of message blocking by Twilio, beginning on July 5, 2023, ultimately leading to a full block of all unregistered U.S.-bound messages sent after August 31, 2023.
> • Effective July 5, 2023, all 10DLC phone numbers used to send SMS and MMS messages to U.S. phone numbers must be fully registered to an approved campaign under your brand. Messages sent using unregistered phone numbers will be subject to a gradual increase of message blocking by Twilio, beginning on July 5, 2023, ultimately leading to a full block of all unregistered U.S.-bound messages sent after August 31, 2023.
Source: https://support.twilio.com/hc/en-us/articles/1260800720410-W...