Starting April 1st, 2021, new legislation in the USA came into effect that impacts businesses using SMS messaging. As of June 1st this year, this legislation became mandatory. So what is A2P 10DLC and how do you register?
What is A2P 10DLC?
Application-to-Person (A2P) 10-digit Long Code (10DLC) allows a business to send SMS messages from a messaging platform to customers over local phone numbers (e.g (123) 456-7890), otherwise called “long codes”. Originally, 10DLC numbers were designed to be used for person-to-person traffic but now businesses can communicate using the numbers. The legislation is intended to protect end users from spam SMS and prevent harsh FCC requirements around spam prevention.
Are shared short codes being banned?
Carriers in the US now require that traffic on shared codes is migrated to 10DLCs or short codes. A shared short code is difficult to control as many businesses can share the same code. This could result in a high risk of shared short codes being used for spam messaging. A couple of carriers now do not allow shared shortcodes with very few exceptions.
Do you need a dedicated short code then?
No. Companies can move to A2P 10DLC which has lower monthly costs and are much faster to provision than short codes.
What do I need to do?
In order to get set up with your A2P 10DLC service, you need to follow a few steps.
1. Choose your provider
If you want to send SMS messages using 3CX, you need to choose one of our supported providers from the following list:
- Preferred & supported providers: Voxtelesys, Skyetel, Flowroute
- Supported dedicated instance only: Bandwidth & Twilio
- 3rd party supported only: Telnyx
2. Register your phone numbers
Once you have chosen your provider, during the setup process you will need to register your phone number(s) to confirm with the legislation. Here are quick links to each provider's guides. Note: as these are external links, we cannot guarantee that the pages are kept up to date.
3. Set up your provider on 3CX
Finally, once you have chosen your provider and registered your numbers with them, you can get set up on 3CX and start sending SMS messages. Follow our guides found above for each provider which will walk you through getting set up.
Use the power of the forum
Don't forget that our forum is a powerful source of information and assistance. Check out our dedicated SMS and SIP trunk categories for more tips and tricks from all our contributors.

