Somewhere around 2021, US mobile carriers decided they had had enough of spam sent from ordinary phone numbers. The result was A2P 10DLC: a registration system that every business texting US customers from a normal 10-digit number now has to go through. It is not optional, it is not particularly complicated, and it is the reason a lot of “our texts stopped delivering” support tickets exist.
I register A2P for clients on GoHighLevel and Twilio every month, and most of the difficulty comes from not knowing what the reviewers are looking for. This guide explains the system in plain English, what each step involves, and how to get approved the first time.
What the letters mean
- A2P — application-to-person. A business system (CRM, booking tool, reminder software) sending texts to people. The opposite is P2P, one person texting another from their phone.
- 10DLC — 10-digit long code. A standard local phone number, as opposed to a short code (5–6 digits) or a toll-free number.
So “A2P 10DLC” simply means business texting from ordinary local numbers. The registration system exists so carriers know which business is behind each number and what kind of messages it sends. Registered traffic is trusted and delivered; unregistered traffic is filtered, throttled or blocked outright.
Who has to register
Any business that sends SMS or MMS to US phone numbers from a 10-digit local number through a software platform. That includes:
- Appointment reminders from a CRM or booking system.
- Missed-call text-back and automated follow-ups.
- Marketing and promotional texts.
- Two-way conversations started by your system (even if a human replies afterwards).
It applies whether you are in the US or not — what matters is that the recipient’s number is a US number. A UK agency texting US clients through GoHighLevel needs to register. It does not apply to texts you send from your own handset, or to toll-free and short-code numbers, which have their own verification processes.
The two-step structure: brand, then campaign
Registration happens through The Campaign Registry (TCR), but you never deal with it directly — your provider (GoHighLevel, Twilio, or whoever supplies the number) submits on your behalf. There are two layers.
1. Brand registration — who you are
You supply the legal business name, business type, tax ID (EIN in the US), address, website and a contact. The registry checks these against public records. The most common failure here is a mismatch: the name entered does not exactly match the name on the EIN record, or the address is a home address that does not match the registered one. Copy the details from your tax documents, character for character.
2. Campaign registration — what you send
A “campaign” is a use case, not a marketing campaign. You describe the type of messages (appointment reminders, customer care, marketing, mixed), provide two to five sample messages, explain how people opt in, and confirm how they can opt out. A reviewer reads this and decides whether it matches the rules. This is where most rejections happen, and almost all of them are avoidable.
The reviewer’s question “Did the recipient clearly agree to receive exactly this kind of message from exactly this business?” Every part of the campaign form — description, samples, opt-in evidence — should answer yes, in the same words.
What a campaign that gets approved looks like
Here is the shape of a submission that passes review, for a typical service business using a CRM:
- Use case: Mixed (or Low Volume Mixed for small senders) — because reminders, follow-ups and occasional promotions all go through the same number.
- Campaign description: “[Business name] sends appointment confirmations and reminders, replies to customer enquiries, and occasional promotional offers to customers who have opted in via our website form or by texting our number. Message frequency varies. Reply STOP to opt out, HELP for help. Message and data rates may apply.”
- Sample messages (include the business name and the opt-out in at least one):
- “Hi Sarah, this is Lakeside Dental. Your appointment is confirmed for Tue 12 Mar at 2:30pm. Reply C to confirm or R to reschedule. Reply STOP to opt out.”
- “Lakeside Dental: thanks for your enquiry — Dr Patel will call you within the hour. Reply STOP to opt out.”
- “Lakeside Dental: our spring whitening offer ends Friday. Book at lakesidedental.com/book. Reply STOP to opt out.”
- Opt-in description: “Customers opt in by submitting the contact or booking form at [website URL], which includes the statement: ‘By providing your phone number you agree to receive SMS from [Business]. Msg & data rates may apply. Reply STOP to unsubscribe.’ A screenshot of the form is attached.”
- Opt-in evidence: A screenshot or link showing that consent language next to the phone field, and a privacy policy page on the website that mentions SMS.
Notice the consistency: the business name appears in every sample, the opt-out instruction appears, the opt-in description points to a real page with visible consent text, and the description matches the samples. Reviewers reject when any of those disagree.
The mistakes that get campaigns rejected
- No consent language on the form. The website form collects a phone number with no mention of SMS. Add the sentence, take the screenshot, then submit.
- Privacy policy says nothing about texting, or says data is shared with third parties for marketing. Add a clear line that phone numbers and consent are not shared for others’ marketing.
- Sample messages without the business name or opt-out. Both should be present.
- Description mentions “leads” or purchased lists. Cold texting to purchased numbers is not permitted. Describe opt-in customers only, because that is who you may text.
- Website unreachable, under construction, or on a different name. The reviewer visits it. Make sure it loads, shows the business name and has the privacy policy linked.
- Brand details that do not match the EIN record. Fixable, but it restarts the clock.
I keep a longer list, with the exact wording that fixes each one, in the A2P registration work I do for clients; the six above cover most of the rejections I am asked to sort out.
Fees and timelines (what to expect)
| Step | Typical cost | Typical time |
|---|---|---|
| Brand registration | One-off registry fee (a few dollars) | Minutes to 2 days |
| Campaign vetting | One-off vetting fee (tens of dollars) | Several business days to a few weeks |
| Campaign monthly fee | A few dollars per month per campaign | Ongoing |
| Rejection and resubmission | Sometimes a repeat vetting fee | Restarts the review |
Fees are set by the registry and passed on by providers; check your provider’s current schedule (Twilio publishes its A2P 10DLC documentation, and GoHighLevel’s help centre covers its own flow). The numbers are small; the time is what hurts, which is why the first submission should be the right one.
What happens while you wait
Until the campaign is approved, texts from the number are either blocked or delivered unreliably. Plan for that: register on day one of a CRM setup, keep email as the fallback channel for confirmations, and do not launch a text-based campaign until you see “approved” in the provider’s dashboard. In a GoHighLevel setup I start the registration before building anything else for exactly this reason.
After approval: staying approved
- Honour STOP immediately and automatically — every platform does this by default; do not override it.
- Keep message content in line with what you registered. If you start sending a new type of message, add a campaign or update the description.
- Watch your opt-out and complaint rates. High rates can get a campaign suspended even after approval.
- Keep the consent language on every form that collects a phone number, including new landing pages.
Further reading: The Campaign Registry.
FAQ
Is A2P 10DLC registration mandatory?
For any business sending application-to-person SMS to US numbers from standard 10-digit long codes, yes. Unregistered traffic is heavily filtered or blocked by the major US carriers. Person-to-person texting from your own phone is not affected.
How long does A2P 10DLC registration take?
Brand registration is often approved within a day or two. Campaign registration is reviewed by a third party and typically takes several business days to a few weeks. Rejections restart the clock, which is why getting the details right the first time matters.
What does A2P registration cost?
Fees are set by the registry and passed through by your provider: a one-off brand registration fee, a one-off campaign vetting fee, and a small monthly fee per campaign. Providers publish the current amounts; expect tens of dollars up front and a few dollars a month, not hundreds.
Do I need an EIN to register?
For a standard business brand in the US, yes — the EIN is matched against the business name and address. Sole proprietors without an EIN can register under a restricted “sole proprietor” type with lower throughput. Businesses outside the US register with their own tax ID.
Stuck in review, or rejected and not sure why? I handle A2P 10DLC registration as part of CRM setups and as a standalone fix — send me the rejection reason and I will tell you what to change.
