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Senddio glossary · Application-to-Person, 10-Digit Long Code

What is A2P 10DLC?

A2P 10DLC (Application-to-Person, 10-Digit Long Code) is the United States carrier registration system for any application that sends SMS messages from a standard 10-digit phone number. Carriers require every business sender to register their brand and the type of messaging they will do, so that legitimate traffic gets prioritised and spam gets filtered.

How A2P 10DLC works in plain English

You register your business identity with The Campaign Registry (TCR), which is the US carrier consortium's database. You then register each "campaign" describing the kind of messages you send — for example, transactional OTPs, marketing promotions, or customer-care replies. Once approved, your numbers get higher throughput and better deliverability.

Why A2P 10DLC matters

Without 10DLC registration, US carriers may rate-limit your messages, reject them, or charge premium per-message fees. Unregistered traffic also has poor deliverability because carriers cannot distinguish you from spammers.

The pain of doing it yourself

Brand registration takes a few days; campaign registration can take one to three weeks, with rejections common when the use case description is not precise enough. The forms ask for opt-in language, message samples, and proof of business identity.

How Senddio handles 10DLC

Senddio provisions managed sender numbers through Telnyx. US 10DLC brand and campaign requirements still depend on the business and use case; provisioning is not a waiver of registration, consent or carrier approval.

Related terms
OTP BSP
FAQ

A2P 10DLC — FAQ

US 10DLC requirements still apply to application traffic on local ten-digit numbers. Confirm the brand, campaign and sender-number setup for your business before sending; do not assume a platform’s registration covers every customer.

A2P 10DLC is US-specific. Other countries have their own sender, consent and registration rules. Check destination support and requirements before sending.

Unregistered or non-compliant traffic may be filtered or rejected. Confirm the sender is associated with the appropriate approved campaign; no route guarantees delivery.

Senddio handles the boring parts of A2P 10DLC for you.

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