What Is A2P 10DLC?

A2P 10DLC ("Application-to-Person, 10-Digit Long Code") is the registration system US and Canadian carriers require before a regular local phone number can send business text messages at scale. If you plan to text US contacts from a standard local number, this registration is required — not optional.

Why it exists

Standard local numbers were originally designed for person-to-person texting between individuals. Carriers now require any business using one to send automated or bulk messages to register who they are and what they're sending, so carriers can tell legitimate business texting apart from spam. Registering gets you a trusted sending path with much better delivery rates; sending unregistered gets your messages aggressively filtered.

The two things you register

• A Brand — your business's verified identity (who's sending).
• A Campaign — what you're sending and why, tied to that brand (why they're sending it, and to whom).

See Registering Your A2P Brand & Campaign for the actual registration walkthrough.

What you get once approved

• A verified sending identity that's far less likely to be filtered as spam
• Access to substantially higher daily sending limits and faster throughput than an unregistered number
• SHAKEN/STIR call authentication automatically included on your voice numbers as well

Do you need this?

If you're only texting Canadian contacts from a Canadian number registered before March 26, 2025, you may be exempt for domestic-only sending — but the moment you text a US number, or use a number purchased after that date, A2P registration applies. When in doubt, register — it's required for essentially all serious business texting in North America.