A2P 10DLC Registration: Getting Your US SMS Actually Delivered

1. What A2P 10DLC is, and why registration exists

A2P stands for Application-to-Person messaging: texts sent by a system or business to a consumer, order updates, two-factor codes, appointment reminders, marketing. It’s the opposite of P2P (person-to-person), the back-and-forth texting between two humans that local numbers were originally built for.

10DLC stands for 10-Digit Long Code, an ordinary US local mobile-capable number (a standard +1 area-code number) as distinct from a 5–6 digit short code or a toll-free number. For years, businesses sent A2P traffic over these local numbers without any formal sanction. Carriers tolerated it until the spam and fraud volume became untenable.

So in 2021, the major US mobile carriers, T-Mobile, AT&T, and Verizon, rolled out the A2P 10DLC framework. The rule is simple: if you send application-to-person traffic over a 10-digit long code, that traffic must be registered. Registered traffic gets a sanctioned path with defined throughput. Unregistered A2P traffic gets heavily filtered, throttled toward zero, blocked, and in T-Mobile’s case hit with per-violation fines levied through your messaging provider.

The goal from the carriers’ side is accountability: tie every sending campaign to a vetted, identifiable business so spam and fraud can be traced and penalised. The result for legitimate senders is a registration step you cannot skip if you want reliable delivery.

2. The two-step registration: Brand → Campaign → numbers

Registration runs through The Campaign Registry (TCR), the central database the carriers use as their source of truth. You don’t usually interact with TCR directly; your messaging provider or CPaaS submits on your behalf. But the structure is always the same three moves.

The Brand step is done once. Campaigns are where the ongoing work lives: each distinct kind of message you send (transactional codes vs. promotional blasts vs. support replies) generally wants its own campaign, because each is vetted and throttled differently. Approval timelines range from near-instant for low-risk use cases to several days when external vetting is involved.

3. Trust score & throughput

When your Brand is registered, it receives a trust score. The score is the single biggest lever on how fast you’re allowed to send. A bare brand registration lands you a low default score; paying for independent external vetting (through TCR-approved vetting providers such as Aegis or WMC Global) re-scores the brand and typically raises it materially.

Higher trust score → higher throughput, measured in messages per second (often written TPS or MPS) toward each carrier, and higher daily message caps, particularly the per-brand daily limit T-Mobile enforces. The table below is directional only: the exact tiers differ by carrier, depend on the campaign use case, and the carriers revise the numbers periodically. Treat it as the shape of the relationship, not a rate card.

The practical takeaway: if you send meaningful volume, budget for vetting. The one-time vetting fee usually pays for itself the first time a campaign would otherwise hit a daily cap and start queuing or dropping messages.

4. Campaign use-case types

Every campaign is registered under a use case. The use case drives both the vetting bar and the throughput you’re granted, a 2FA campaign and a marketing campaign with identical brands are treated very differently. These are the common ones.

Pick the narrowest use case that covers what you actually send. Registering everything as “mixed” to save effort tends to cost more and invite stricter filtering than splitting transactional and promotional traffic into separate, honestly-scoped campaigns.

5. Fees & consent

A2P 10DLC carries a layered fee structure. None of the numbers are enormous individually, but they stack, and several recur monthly. Expect, directionally:

• One-time TCR brand registration fee, a small flat charge to register the brand.
• External vetting fee (optional but recommended at volume), a one-time charge per brand to raise the trust score.
• Campaign fees, typically a recurring monthly charge per campaign, with the rate varying by use case (marketing campaigns cost more than low-volume mixed).
• Carrier pass-through surcharges, the carriers levy their own fees on top. These include per-campaign charges and, critically, per-message carrier fees that T-Mobile, AT&T, and Verizon add to each segment delivered. At volume, the per-message surcharges dwarf the registration fees.

Your messaging provider passes these through, sometimes bundled, sometimes itemised, ask for the breakdown before you forecast costs.

Separate from fees, and non-negotiable: consent. Every campaign must document how consumers opt in to receive your messages, and the sample opt-in language is part of the registration itself. This is where 10DLC meets the TCPA (Telephone Consumer Protection Act): marketing messages require prior express written consent, opt-in must be unambiguous and not buried, and every message stream needs a working opt-out (STOP) honoured automatically. Registration approves the mechanics; the TCPA governs your legal exposure. Skimping on documented opt-in is both a compliance risk and a fast route to campaign rejection.

6. 10DLC vs toll-free SMS vs short code

10DLC is the default for most senders, but it isn’t the only sanctioned A2P path. The two alternatives sit at different points on the throughput-and-cost curve.

Note that toll-free verification is its own registration regime, not part of 10DLC, but with the same spirit: you verify the business and document opt-in, and unverified toll-free SMS is filtered just like unregistered 10DLC. Short codes carry the highest throughput and the highest cost, with multi-week provisioning. For the large majority of senders, a well-vetted 10DLC brand is the right starting point.

7. How DIDHub helps

DIDHub provides US mobile and SMS-capable numbers, the 10-digit long codes your A2P traffic runs over. Provisioning a number is the easy part and it’s where we sit. We’ll be direct about the division of labour, because A2P 10DLC is a process you participate in, not one anyone can switch off on your behalf.

What DIDHub does: supplies the SMS-capable 10DLC numbers, connects them to the messaging path, and guides you through submitting your Brand and Campaign registrations to The Campaign Registry, including assigning numbers to an approved campaign once it clears.

What you must do: register your own Brand (your legal entity, EIN, address), define and submit each Campaign with real sample messages, and document how your recipients opt in. We can’t invent your consent flow or vet your business identity for you, that’s yours to own, and it’s also what keeps you on the right side of the TCPA. Nobody legitimately bypasses registration; any provider claiming they can is inviting blocks and fines onto your traffic.

If you’re choosing between a local long code, a toll-free number, or a short code, our DID number types guide breaks down the tradeoffs, and the SMS/MMS page covers what our numbers support. For help scoping a brand and campaign setup for your volume, reach out to [email protected], we’ll tell you honestly what registration your use case needs before you send a single message.

Bottom line

Register before you send. US carriers have required A2P 10DLC registration since 2021, and unregistered local-number traffic is filtered, throttled, blocked, and fined, quietly, so you often don’t even see the failures. Expect two steps (Brand then Campaign), expect to assign your numbers to an approved campaign, and expect fees: one-time registration, optional vetting to lift your trust score and throughput, recurring per-campaign charges, and per-message carrier surcharges that grow with volume. Document your opt-in properly, it’s both a registration requirement and your TCPA shield. Do it once, do it honestly, and your US SMS actually gets delivered.

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