A2P 10DLC for HubSpot users: get registered without getting blocked
US carriers block unregistered business SMS outright. A plain-English walkthrough of Twilio's A2P 10DLC registration, written for HubSpot admins rather than developers.
August 11, 2026 · 7 min read
You set up SMS in HubSpot. You send a test message. Your workflow reports success, your SMS tool shows the message as sent, and the person you texted never receives anything.
That is what unregistered A2P traffic looks like from the inside. Nothing errors. Nothing warns you. The message simply stops at the carrier.
This is the version of Twilio's A2P 10DLC documentation written for the person who administers a HubSpot account, not for a developer. If you've been staring at words like "brand", "campaign", and "Trust Hub" wondering which of them you actually need, start here.
What A2P 10DLC is, in one paragraph
A2P means application-to-person: a computer sending a text to a human, as opposed to two people texting each other. 10DLC means a ten-digit long code — an ordinary local phone number, as opposed to a short code or a toll-free number. Put together, A2P 10DLC is the US carriers' scheme for registering businesses that send automated texts from normal phone numbers. You tell the carriers who you are and what you'll send; they decide whether to deliver it.
Why it matters more than it did
Carriers used to filter unregistered business messages — some got through, some didn't, and delivery was mysterious. Since early 2025 the major US carriers block unregistered A2P traffic outright.
There's no partial delivery to diagnose and no warning in your CRM. From HubSpot's side the workflow step succeeded. From Twilio's side the message was accepted. The failure happens one hop further on, where neither system is looking.
Registration attaches to your phone number and your business, not to your software. Switching SMS apps doesn't change it. Building the integration yourself doesn't avoid it. If you send business texts to US numbers from a local number, you register.
Do you need to do this?
| Situation | What you need |
|---|---|
| Texting US numbers from a US local number | A2P 10DLC registration |
| Texting US numbers from a toll-free number | Toll-Free Verification instead — a different form, similar effort |
| Texting Canadian numbers | Lighter requirements, but carriers still expect registered traffic |
| Texting outside North America | Different rules per country; check Twilio's guidelines for each |
| Still testing, nobody real is receiving anything | Nothing yet — see the testing note below |
Before you open the form
Twilio's registration asks for things most people don't have in front of them. Gather these first and the whole thing takes fifteen minutes rather than three sittings:
- Your legal business name and registered address, exactly as they appear on your incorporation documents. Not your trading name, not your website's "about" wording. Mismatches are the most common rejection.
- Your EIN, or the equivalent tax ID outside the US. No EIN? There's a Sole Proprietor route with lower sending limits.
- Your company website, live, with a privacy policy on it that doesn't require a login. Reviewers open it.
- An authorised contact — a real person's name, job title, and business email at your domain.
- Evidence of how people opt in. A link to the form with the consent checkbox, or a screenshot showing the exact wording next to the box. This is the part that gets applications rejected.
- Two sample messages you'd genuinely send.
Registration requires a paid Twilio account. Upgrading is a one-time payment and your trial credit carries over.
The three steps
Everything happens in the Twilio Console, under Messaging → Regulatory Compliance. Nothing here happens in HubSpot.
1. Customer profile
Twilio calls this Trust Hub. It's your business identity: legal name, address, tax ID, website, authorised contact. You fill it in once and everything else draws from it.
2. Brand
Your company as the carriers see it. Twilio passes your details to The Campaign Registry, which checks them against public business records.
Most businesses register as Standard. Under roughly 3,000 messages a day, Low-Volume Standard is cheaper with the same approval path. Without an EIN, answer "no" to the tax ID question and Twilio routes you to the Sole Proprietor path, which has tighter daily limits.
Brand approval usually comes back within hours.
3. Campaign
What you'll actually text people about. This is the slow step — ten to fifteen days at the moment — and the one that gets rejected, so it deserves your attention.
Use case. Pick the one that matches your traffic: customer care, account notifications, marketing, two-factor codes. Be accurate. Traffic that doesn't match its registered use case gets campaigns suspended later, and that's much worse than a slow approval.
Description. Write two or three real sentences describing who you text and why. This gets approved:
Appointment reminders and follow-up messages sent to customers who have booked a consultation through our website and opted in to text updates.
This does not:
Notifications.
Sample messages. Write two you would actually send. Include your business name — most recipients don't have your number saved — and put an opt-out line on at least one. Use square brackets for anything that varies:
Hi [name], this is [Business] confirming your appointment on [date]
at [time]. Reply STOP to opt out.
Consent. Show where and how someone agrees to be texted. A URL to the live form is best; a screenshot showing the checkbox and its wording works too. Pre-ticked boxes, consent buried in terms nobody sees, and purchased lists all get rejected — and should.
Then attach your number
Once the campaign is approved, add your phone number to the Messaging Service Twilio created for it: open the Messaging Service, click Add Senders, pick your number. Registration only takes effect for numbers attached to the campaign.
Testing while you wait
Two weeks is a long time to sit still, and you don't have to.
Twilio's Virtual Phone — Console → Messaging → Try it out → Virtual Phone — is a phone number that lives in your browser. It works in both directions and ignores carrier registration entirely. It's the best way to prove your HubSpot workflows and inbox routing behave correctly before real messages are on the line.
Verified numbers on a trial account can also receive messages, with a Twilio trial notice prepended.
Neither proves deliverability to real customers. That only registration does.
If your campaign is rejected
It happens, it's usually one specific thing, and you resubmit rather than starting over.
| Reason | Fix |
|---|---|
| Consent evidence unclear | Link the live page with the opt-in checkbox, or attach a screenshot showing the exact wording |
| Sample messages too vague | Rewrite as real messages, with your business name and a STOP line |
| No privacy policy on the website | Publish one, reachable without logging in, and resubmit |
| Business details don't match records | Use the exact registered legal name and address |
| Use case doesn't match the samples | Change the use case to the one that describes your messages |
After approval: the ongoing obligations
Registration isn't a one-off box to tick.
Honour STOP. Anyone can text STOP to opt out, and after that Twilio refuses messages to them. You'll see those as failed messages, which is the system working. Don't text them from a different number — that's the fastest route to a suspended campaign and, in the US, real legal exposure.
Answer HELP. Recipients must be able to text HELP and find out who is texting them. Twilio handles the automatic reply.
Keep your registration honest. If your use case changes — you registered for appointment reminders and now you're sending promotions — update the campaign. Carriers audit against what you registered.
Mind the throughput. Registration determines how many messages per second you can send. If you're sending a large batch from a HubSpot workflow it will meter itself out over time rather than going instantly, and that's normal.
How this shows up in HubSpot
If you're using an SMS integration and messages aren't arriving, the tell is a delivery status of undelivered, sometimes with error code 30034, on messages your workflow reported as successful. Anything that surfaces Twilio's delivery status will show it; anything that only reports "sent" will not, which is a good reason to check whether yours does.
Our own app shows the status and the reason in plain English on the message log, and our A2P guide has the same steps written as product documentation.
The short version
If you're texting US customers from HubSpot, register before you build the rest. Brand approval takes hours, campaign approval takes one to two weeks, and unregistered messages don't get delivered at all. Everything else in your SMS setup is reversible in an afternoon. This is the one that costs you a fortnight if you leave it until last.