10DLC registration

10DLC ("10-digit long code") is the US carrier program that decides which businesses are allowed to send SMS from local phone numbers, and how fast. Every business that sends application-to-person (A2P) SMS in the US has to be on file with The Campaign Registry (TCR) as a brand running one or more campaigns. Carriers then use that registration to set rate limits and to decide whether to deliver, throttle, or block your messages.

When you provision a local number on Inkbox, it's automatically attached to Inkbox's own brand and campaign so it can send right away — but on tight rate limits. To unlock your own throughput, register your own brand and campaign, then route your numbers through them. The whole flow is configurable from the Console.

Toll-free numbers do not use 10DLC and don't need this flow. SMS on toll-free numbers is not currently supported on Inkbox at all (voice still works). To send SMS, provision a local number.

Have these on hand before you open the form. You can save a draft and come back, but the registry will reject submissions that don't match official records exactly.

For the brand (your business identity):

• Legal entity type — private/public for-profit, non-profit, government, or sole proprietor.
• Legal company name as filed with the IRS and your EIN (or the equivalent if non-US).
• Registered business address (street, city, state, ZIP, country).
• Business contact email and phone.
• Public website URL.
• Your industry vertical (e.g. retail, healthcare, financial, communication).
• For public companies: stock ticker and exchange.
• For sole proprietors: a mobile phone you can receive an SMS verification code on.

For the campaign (what your messages are for):

• A use case (e.g. customer care, account notification, 2FA, marketing, mixed).
• A short description of what your agents will text recipients about.
• A short description of how recipients opt in (the "message flow").
• Four sample messages that look like the real thing your agents will send — TCR reviewers compare submitted samples against actual traffic.
• The exact opt-in / opt-out / help keywords and auto-replies you want to use. Defaults are pre-filled (STOP, HELP, etc.) and follow CTIA messaging best practices — leave them as-is unless you have a reason to change them.
• Public URLs for your privacy policy and terms & conditions. Both pages must mention SMS, that message and data rates may apply, and that recipients can opt out by replying STOP.

1. Open the Console → Configuration → 10DLC tab.
2. Click Register brand and fill out the form using the details above.
3. Submit. The brand status will move to Verifying while the registry runs identity checks.
4. Most brands reach Verified within a few hours; some take 1–2 business days. Sole-proprietor brands need an extra step (see below).

Sole proprietors: SMS verification

If you registered as a sole proprietor, the brand stays in Verifying until you confirm the mobile number you registered. After submission, the page shows a Verify mobile phone button. Click it, the registry texts a 6-digit PIN to that number, paste the PIN back into the dialog. Once verified, the brand flips to Verified and you can move on.

Brand statuses

You can only register a campaign once your brand is Verified (or Vetted).

1. Back on the 10DLC tab, click Register campaign.
2. Pick the use case that matches what your agents will actually send. Picking the wrong use case is the most common cause of carrier rejection.
3. Fill in the description, sample messages, and opt-in/keywords/auto-replies. Provide your privacy policy and terms & conditions URLs.
4. Submit. The campaign goes through two reviews — the registry first, then each major US mobile carrier.

Campaign statuses

For a deeper explanation of how carriers score campaigns and assign throughput tiers, The Campaign Registry's resource center is the authoritative public reference.

Once the campaign is Approved, switch your local numbers over.

1. On the 10DLC tab, find the Default SMS campaign dropdown at the top of the page.
2. Switch it from Inkbox to Your 10DLC profile.
3. All of your local US numbers move onto your campaign within a few minutes. Toll-free numbers are unaffected.

You can flip back to Inkbox at any time — your campaign stays registered.

Per-number propagation window

A number takes about 10–15 minutes to fully attach to a new campaign downstream. Sends during that window return 409 sender_sms_pending. The Console flags affected numbers with a SMS pending badge until they're ready. See Texts for the full error reference.

A "send" is one outbound POST /api/v1/phone/numbers/{phone_number_id}/texts request, regardless of whether the message gets split into multiple SMS segments downstream.

Every send response — success or failure — includes X-RateLimit-Limit, X-RateLimit-Remaining, and X-RateLimit-Reset so you can pace traffic. On a 429, you'll also get Retry-After (seconds).

The error body when you hit the shared-profile limit:

JSON

If your traffic is bursty, slow it to under one send every few minutes per number on the Inkbox campaign, or register your own.

The Console doesn't support editing a submitted brand or campaign — to change anything, delete and re-register.

• Delete a brand to start over from scratch. Deleting a brand cascades to its campaign and reverts every local number to the Inkbox campaign. The Console asks you to type the brand name to confirm.
• Delete a campaign if it was rejected and you want to resubmit with different metadata. The Console asks you to type DELETE CAMPAIGN to confirm.