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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. Register your business as a brand and describe its messaging use case in a campaign. Carriers then use that registration to set rate limits and to decide whether to deliver, throttle, or block your messages. Inkbox starts registration for new local numbers on Inkbox’s own brand and campaign. Wait until the number’s sms_status is ready before sending. To use your own throughput allowance, register your own brand and campaign, then route your numbers through them. Configure the flow in the Inkbox Console. Running your own campaign costs $20/month on top of your identity fees — see pricing. The charge applies only while your campaign is approved by carriers: you pay nothing while registration is under review, and the charge stops if approval lapses or you delete the campaign.

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Do you need to register?

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Before you start

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. 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.) — 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.

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Step 1: Register your brand

  1. Open the Inkbox Console → Phone → Compliance (10DLC).
  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).

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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.

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Brand statuses

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Step 2: Register your campaign

You can only register a campaign once your brand is Verified (or Vetted).
  1. Back on the Compliance (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.

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Campaign statuses

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Step 3: Route your numbers through your campaign

Once the campaign is Approved, switch your local numbers over.
  1. On the Compliance (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 numbers move onto your campaign within a few minutes.
You can flip back to Inkbox at any time — your campaign stays registered.

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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.

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Rate limits

A “recipient send” is one outbound recipient on POST /api/v1/phone/numbers/{phone_number_id}/texts. A 3-recipient group message counts as 3 recipient sends. Group MMS and MMS sends from 10DLC local numbers are beta. Even with an approved campaign and ready sender, some carriers may reject group chats or MMS from 10DLC numbers. 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:
If your traffic is bursty, slow it to under one send every few minutes per number on the Inkbox campaign, or register your own.

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Editing a campaign

Open Phone → Compliance (10DLC) in the Inkbox Console and select Edit campaign on your campaign card. Correct the fields, then review the submission button:
  • Save changes updates an existing campaign when you change only editable fields, such as sample messages or message flow.
  • Resubmit campaign starts a new review when you change registration fields, such as the use case, description, or keywords.
Use the same editor to correct a rejected campaign. Rejected campaigns require resubmission even when you change only sample messages.

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Deleting a brand or campaign

  • Delete a brand to start over from scratch. Deleting a brand also deletes its campaign and moves your local numbers to the Inkbox campaign. The Console asks you to type the brand name to confirm.
  • Delete a campaign to remove it. The Console asks you to type DELETE CAMPAIGN to confirm. You can edit an existing campaign without deleting it yourself.

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Troubleshooting

The registry is matching the legal name + EIN you submitted against IRS records. The most common cause of a delay is a mismatch — even a trailing “Inc.” or a wrong EIN digit fails the match.If yours is past 24 hours, email hello@inkbox.ai with your organization name and the brand display name — we can pull the registry-side state for you and tell you exactly what’s wrong. In most cases the fix is to delete the brand, correct the mismatched field against your most recent IRS filing, and re-register.
The campaign card on the Compliance (10DLC) tab shows the rejection reason. The most common reasons:
  • Sample messages don’t match the use case. If you picked “customer care” but your samples look promotional, carriers reject. Either change the use case or rewrite the samples to fit.
  • Missing opt-in language. Your opt-in flow has to be described in the message flow field, and your privacy policy / terms pages have to mention SMS, message and data rates, and STOP-to-opt-out.
  • Public URLs aren’t reachable. Make sure the privacy policy and terms URLs you submitted are live and don’t require login.
Select Edit campaign, correct the metadata, then select Resubmit campaign.
That’s expected. Routing changes take ~10–15 minutes per number to propagate downstream. Wait for the SMS pending badge in the Console to clear and try again.
Each Inkbox organization can have one brand and one campaign at a time today. If you need to send for materially different use cases (e.g. one-time-password traffic alongside marketing), email hello@inkbox.ai.