Search Results

10DLC and Toll-Free A2P Compliance

U.S. A2P Customer Obligations

Aerialink is committed to creating a healthy messaging ecosystem that serves all participants and to keeping our customers informed about recent changes in the industry, including the CTIA Messaging Principles and Best Practices.

All customers sending A2P traffic are subject to CTIA guidelines.

The number types that deliver messages over an A2P service include:
short codes
toll-free numbers (800, 833, 844, 855,866, 877, 888)
standard 10 digit numbers on the following schedule:

  • Verizon MMS A2P service rolled out Jan 14, 2020
  • Verizon SMS A2P service effective Feb 1, 2020
  • Other carriers A2P service – TBA

Note that any and all participating carriers may include their own, additional rules and regulations for what constitutes A2P messaging above and beyond the definitions found in the CTIA Best Practices Guidelines. We recommend that you check these pages regularly for updates as the telecommunications ecosystem continues to evolve. As such, the information below may be updated or changed without notice.

The following guidelines should be maintained by all Aerialink customers for compliant A2P messaging. In addition to our Acceptable Use Policy, Aerialink customers using A2P messaging routes:

  1. Must obtain express consent prior to sending messages to any recipients.
  2. Must provide an opt-out method, permitting end-users to decline to receive any further messages.
  3. Must seek independent legal consent regarding opt-ins, opt-outs and the retention of these records.
  4. Must not send messages violating CTIA or carrier rules or regulations for acceptable A2P messaging. Note that these rules and regulations are subject to change. Those changes will be reflected in the Aerialink Acceptable Use Policy.
  5. Understand that carriers reserve the right to re-evaluate messaging use-cases at any time and may shut down existing messaging programs at their discretion.
  6. Must, if intending to resell A2P services, assume responsibility for the maintenance of compliant rules and regulations equal to or greater than those imposed by the CTIA, carriers and Aerialink.
  7. Must, if intending to resell A2P services, obtain use-case information from all clients and maintain the right to audit said programs. Aerialink customers must be able to provide this information to Aerialink upon request.
  8. Must be prepared to block any future traffic to Deactivated Subscriber Numbers (see below).
  9. Must not use A2P messaging services to send Protected Health Information.
  10. Must provide appropriate security and privacy controls to protect subscribers and maintain opt-in and opt-out integrity and full confidentiality of end-user information.
  11. Must provide terms of service and privacy policy.

Deactivated Subscriber Numbers

Carriers may periodically provide Aerialink lists of subscriber numbers whose numbers have been deactivated at the carrier level. Aerialink will forward these to Aerialink customers, who will then update their systems to block any further A2P messages from being sent to any and all recipients in the deactivated subscribers list.


Aerialink Compliance articles are for informational use only. They do not constitute, and should not be taken as or in place of, legal advice. Aerialink customers are responsible for meeting all legal requirements applicable to their programs and are strongly encouraged to consult formal legal counsel.