A2P 10DLC in plain language
A2P stands for application-to-person. It describes text messages sent by a business or software application to a person, such as appointment reminders, order updates, verification codes and promotional offers. This is different from P2P, or person-to-person, texting, where two people message each other from their own phones.
10DLC stands for 10-digit long code, which is the ordinary local phone number format used in the United States, for example a number with a familiar area code. A2P 10DLC is the system US mobile carriers use to identify businesses that send texts from those local numbers. Instead of letting any application send any volume of messages anonymously, carriers ask businesses to register who they are and what they send.
Registered traffic can be identified and delivered. Unregistered traffic is increasingly filtered or blocked.
Why carriers introduced registration
Standard local numbers were designed for people texting each other, not for businesses sending messages at scale. As more businesses, and more spammers, used them for bulk messaging, carriers needed a way to tell legitimate senders from abusers. Phishing, scam links and unwanted marketing all travel by text, and recipients tend to blame the carrier as well as the sender.
Registration gives carriers a record of the business behind a number, the kind of messages it sends and how its customers agree to receive them. That record lets them deliver legitimate traffic with confidence and filter the rest.
Who needs to register
If your business sends text messages to US mobile numbers from a 10-digit local number through a messaging platform, you need to register. This applies whether you send a few messages a day or thousands, although the type of registration and the message limits that apply differ. Typical senders include:
- Local service businesses sending appointment reminders and confirmations
- Clinics, salons, gyms and dealerships following up with customers
- Marketing and lead generation agencies that send on behalf of clients
- Software platforms that let their customers send text messages
- Businesses sending promotions, review requests or account notifications
- Nonprofits, schools and community organizations sending announcements
If you only text customers occasionally from your personal phone, you are not sending application-to-person traffic. The moment messages come from software, a CRM or a platform, registration applies.
The two parts of registration
1. Brand registration
The brand is your business identity. You provide the legal business name, tax ID, entity type, address, website and a contact. This is submitted to The Campaign Registry, the central registry that carriers use, and checked against official records. Read more on our brand registration page.
2. Campaign registration
The campaign describes what you send. You choose a use case, describe the messages, provide sample messages, explain how customers opt in and how they opt out. A reviewer checks that your description, samples, website and consent flow all tell the same story. Read more on our campaign registration page.
Once a campaign is approved, your phone numbers are attached to it in your messaging platform and can send under that registration.
How a registered message travels
- Your business sends a message through a messaging platform, using a local number assigned to an approved campaign.
- The platform passes the message to the carrier network along with the registration it belongs to.
- The carrier checks the campaign record: who the brand is, what the campaign is for, and what limits apply.
- If the message fits the registration and the limits, it is delivered to the recipient's phone.
- If the recipient replies STOP, the platform records the opt-out and stops further messages to that number.
Trust scores, vetting and message limits
Approved brands receive a trust score based on the information they provided, and that score influences how many messages campaigns are allowed to send. Businesses that need higher volumes can request additional external vetting, which is a separate review of the business. Limits can differ by carrier, by brand type and by campaign use case, so two businesses with approved registrations may have very different sending capacity.
This is one more reason accurate, complete details matter at the start. A thin or inconsistent brand record can limit what you can send even after approval.
10DLC, toll-free numbers and short codes
There are three common ways for US businesses to send text messages. Each has its own process:
- 10DLC (local numbers): registered through brand and campaign registration. Familiar local area codes and the most common choice for small businesses and local brands.
- Toll-free numbers: use a separate toll-free verification process.
- Short codes: five or six digit numbers with their own application process, used for high-volume programs.
This site focuses on 10DLC registration for local numbers.
What happens if you do not register
Carriers filter or block messages from unregistered traffic on 10-digit numbers. In practice this can mean:
- Messages that never reach customers, often with no visible error
- Lower delivery rates and more filtered messages as enforcement tightens
- Messaging platforms restricting or suspending sending until registration is complete
- Missed appointments, unconfirmed bookings and lost follow-ups
Because the failure is often silent, businesses sometimes only notice when customers stop replying.
Fees you should expect
Registration involves fees charged by the registry, the carriers or your messaging platform, and these differ between providers and can change. They usually include a one-time brand registration charge, a campaign registration charge, and recurring campaign fees. Check your platform for current amounts. Our service fee is separate and quoted after you send a request.
A simple checklist to get registered
- Confirm your legal business name, EIN, entity type and address.
- Make sure your website is live and shows a privacy policy and SMS terms.
- Add consent language to every form that collects a phone number.
- Decide which kinds of messages you send and pick the matching use case.
- Write realistic sample messages that name your business.
- Submit the brand, then the campaign, then attach your numbers.
Common mistakes to avoid
- Using a trade name instead of the legal name when registering the brand
- Choosing the easiest use case instead of the accurate one
- Describing opt-in in general terms without showing the actual form
- Using public link shorteners in sample messages
- Texting people whose numbers came from a purchased or shared list
- Resubmitting a rejected registration without changing what caused the rejection
Key terms
- The Campaign Registry (TCR)
- The central registry where brands and campaigns are registered and vetted for US carriers.
- Brand
- The registered identity of the business sending the messages.
- Campaign
- A registered description of a messaging program: use case, samples, opt-in and opt-out.
- Use case
- The category of messages sent, such as customer care, account notifications, marketing or a mix.
- Messaging platform
- The software or provider you send through. It submits your registration and attaches numbers.
- Carrier
- The mobile network, such as AT&T, T-Mobile or Verizon, that delivers the message to the recipient.
- Trust score
- A rating attached to a brand that influences message limits.
- Vetting
- An additional review of a brand, available when higher volume is needed.
- Opt-in
- The way a person agrees to receive your messages.
- Opt-out
- The way a person stops receiving them, for example by replying STOP.
How we help
We register your brand and campaign for you, check your website and consent flow before anything is submitted, and fix registrations that were rejected. See how the process works, learn about opt-in and consent, or look at the most common rejection causes.
This page is general information about registration requirements, not legal advice.