A2P 10DLC

The registration system US wireless carriers use to verify business text messages sent from regular 10-digit phone numbers. Required for any business that texts customers.

Also known as: Application-to-Person 10-Digit Long Code, 10DLC

A2P 10DLC stands for Application-to-Person 10-Digit Long Code. It is the registration system US wireless carriers (AT&T, Verizon, T-Mobile) use to verify business text messages sent from standard 10-digit phone numbers.

In plain English: if your business sends texts to customers in the United States, A2P 10DLC registration is mandatory. Unregistered traffic is blocked.

What Changed

For years, the rules existed but enforcement was loose. That ended on February 1, 2025, when all major US carriers began rejecting 100% of unregistered 10DLC traffic. Before that date, unregistered messages were delayed or filtered. After it, they’re outright blocked.

If you’ve noticed a bunch of your business texts not getting through in 2025 or 2026, A2P 10DLC is almost always the cause.

How Registration Works

Two pieces have to be registered with The Campaign Registry (TCR), the central system US carriers use:

  1. Brand — your business identity, including legal name, EIN, address, and website.
  2. Campaign — the type of texts you send (appointment reminders, billing, support, etc.) along with sample messages and an opt-in description.

Once both are approved, your phone number is connected to the campaign and your texts route through it as verified business traffic.

Cost

Most small service businesses pay $15–$20/month total in carrier fees once registered. A reputable messaging platform bakes this into your subscription.

What Happens If You Skip It

Your texts get filtered or rejected by the carriers. You may not realize it because the messages appear sent on your end — they just never arrive on the customer’s phone. Delivery rates of 30–50% are common for unregistered traffic.

For the full guide, read our A2P 10DLC compliance guide. If you want a business phone that handles registration for you, see our Business Phone System feature page.

Related terms

TCPA

The Telephone Consumer Protection Act — the federal law that governs how US businesses can call and text consumers. Sets the rules for opt-in consent and STOP requests.

Get the platform that does all of this for you.

Kairvio is the all-in-one app for service businesses. Calls, AI, scheduling, invoicing, payments — in one place.

Start Your Free Trial