What is 10DLC?
10DLC stands for 10-digit long code: a standard local phone number used to send application-to-person (A2P) text messages. It is the channel most ISPs use for subscriber texting because the number looks and behaves like a normal local number, supports two-way replies and costs far less than a short code.
Carriers built A2P 10DLC as a verified route: traffic is only delivered when the sender and the purpose of the messages are known in advance. Registration runs through The Campaign Registry (TCR), the third-party registry the major carriers selected. Your messaging provider (the platform that owns your numbers) submits the registration on your behalf and attaches a Campaign ID to each number.
What do you register: brand and campaign?
- Brand
- Your company. Registered once, with your exact legal name as it appears with the IRS and your EIN, plus address, website and contact details. A mismatch between the legal name and the EIN is one of the most common reasons registrations stall.
- Campaign
- One messaging purpose. It describes what you send and why, how subscribers opt in, how they opt out and get help, and includes sample messages. Each number that sends texts must be attached to a registered campaign.
- Vetting
- Optional reviews of your brand that can raise throughput with some carriers. Standard vetting is automated; enhanced vetting is a longer manual review.
Brands are registered individually, so if you operate several ISP brands (for example after an acquisition) plan one brand registration for each legal entity that sends.
Which ISP messages need a campaign?
Every automated text to subscribers does. The practical question is how to group them into campaigns so each one describes its traffic accurately:
| Message | Typical campaign purpose | Consent to plan for |
|---|---|---|
| Outage and maintenance notices | Account notifications | Collected at signup, tied to service updates |
| Install and repair appointment reminders | Account or customer-care notifications | Collected when the appointment is booked |
| Payment reminders with a payment link | Account notifications | Collected at signup or in the billing portal |
| Two-way support conversations | Customer care | The subscriber texts first, or opts in at signup |
| One-time login or verification codes | Two-factor authentication | Requested by the subscriber in the moment |
| Plan upgrades and promotions | Marketing | Separate, explicit marketing consent |
Keep marketing out of your service campaigns. A campaign registered for account notifications that starts sending upgrade offers no longer matches its registration, and carriers can suspend it.
What are the consent and opt-out rules?
Two sets of rules apply at once. The TCPA and FCC rules restrict autodialed, prerecorded and artificial-voice calls to wireless numbers without the recipient's prior express consent, and the FCC treats texts sent with an autodialer as calls. The FCC has also made clear that consumers can revoke consent by any reasonable means. On top of the law, the carrier industry's CTIA Messaging Principles and Best Practices set expectations that carriers enforce through 10DLC.
- Get consent that matches the purpose: service messages and marketing need separate consent.
- Say what subscribers will receive, and roughly how often, when they opt in.
- Tell them how to stop. Standard STOP wording, and act on natural-language opt-outs such as “unsubscribe” or “cancel” too.
- Support HELP replies with a way to reach you.
- Honor an opt-out across every system that texts on your behalf, not just the one that received it.
What happens if you text without registering?
The messages do not arrive. The industry began blocking unregistered A2P 10DLC traffic on February 1, 2025, and some platforms, such as Twilio, blocked it earlier on their own networks. Subscribers never see the outage notice or the payment reminder, and nothing on your side necessarily looks broken — the send simply fails downstream. Campaigns that send content outside their registration can also be suspended or penalized by carriers.
How do you get registered? A checklist
| Check | Why it matters |
|---|---|
Legal name and EIN match IRS records exactly Brand registration verifies both; mismatches are rejected. | Brand registration verifies both; mismatches are rejected. |
Every system that texts subscribers is inventoried Billing, support, field scheduling and marketing tools often send from different numbers. | Billing, support, field scheduling and marketing tools often send from different numbers. |
Each message type is mapped to a campaign Traffic must match the campaign it is registered under. | Traffic must match the campaign it is registered under. |
Opt-in language is written down where subscribers see it Campaigns ask how consent is collected; reviewers check it. | Campaigns ask how consent is collected; reviewers check it. |
Sample messages include your brand name and STOP wording Samples are part of the campaign submission. | Samples are part of the campaign submission. |
Opt-outs sync across all sending systems A STOP in one tool must stop texts from every tool. | A STOP in one tool must stop texts from every tool. |
Every sending number has a Campaign ID attached Unattached numbers send unregistered traffic, which is blocked. | Unattached numbers send unregistered traffic, which is blocked. |
- DueSep 01
- ReminderSep 08
- SuspendedSep 15
- Paid via linkSep 18 14:02
- ReconnectedSep 18 14:04
Where does Inerxia fit?
SMS over 10DLC is one of the channels Inerxia's AI agents and shared inbox work in. The billing and collections agent sends payment reminders with your own payment link, the field operations agent confirms and reschedules appointments, and the support agent resolves cases in two-way text threads.
Registration is per brand and campaign, not per tool: every system that texts subscribers on your behalf needs to be covered by a registered campaign. Ask any vendor — us included — which campaign its traffic runs under and how opt-outs are shared.
Sources
Checked September 24, 2026. This guide is orientation, not legal advice; confirm your consent language and registrations with counsel and your messaging provider.