← Glossary

A2P 10DLC

Email & SMS delivery

Also called: 10DLC, 10DLC registration, A2P messaging

A2P 10DLC is the US carrier framework for application-to-person messaging sent from ordinary ten-digit long code numbers. Senders register their business and campaign with the carriers, and unregistered traffic is throttled or filtered rather than delivered.

This is a compliance step that behaves like an infrastructure step. Skipping it does not produce an error, it produces silence: messages accepted by your provider and quietly dropped downstream, which is a considerably worse failure mode than a rejection.

Registration involves declaring the business and the campaign — the use case, sample message content, and how contacts opted in. Vague answers get rejected, so it goes faster when the funnel genuinely has an opt-in you can describe.

Throughput follows registration. Registered campaigns get message-per-second limits based on trust, which is the practical difference between a reminder blast that lands in minutes and one that trickles out for an hour.

How it works in FrazzleCRM

  • SMS uses your own Twilio credentials, so registration happens in your Twilio console against your own brand.
  • The Twilio setup guide covers buying an SMS-capable number and registering for 10DLC before US sending.
  • No per-message markup is added on any plan — you pay Twilio directly at their rates.
  • Send windows and Do Not Disturb are separate from carrier rules and cover the courtesy and quiet-hours side that registration does not.

Where teams get this wrong

Unregistered US long-code traffic gets filtered without an error surfacing anywhere in your automation. If SMS steps report as sent and nobody receives them, check registration status before debugging the flow.

Common questions

Does 10DLC apply outside the United States?

No — it is a US carrier framework. Other countries have their own rules, including sender-id registration in some markets and outright bans on unsolicited messaging in others.

Do I need it for a handful of appointment reminders?

For US long-code sending, effectively yes. Filtering does not distinguish between low and high volume, and appointment reminders are exactly the messages you cannot afford to have silently dropped.

See it on a real map

Free templates where this shows up as an actual node. Clone one and the diagram runs as the automation.

Related terms

Or browse all 24 terms — grouped by what part of the funnel they belong to.

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