DCA? CSP? TCR? How to speak 10DLC

Your Guide To the Acronyms of 10DLC & The Campaign Registry

What is 10DLC?

You won’t have to spend much time in the world of 10DLC messaging before you hear an acronym dropped into an email or conversation. In this post, we aim to not only decode those confusing acronyms, but also explain what each one means in the 10DLC process.

As phone numbers in the North American region are 10 digits long, 10DLC simply means 10 digit long code and looks like a regular telephone number - e.g. 2125552368. The term “long code” helps distinguish it from its shorter counterpart, the five or six digit short code.

10DLC is a Mobile Network Operator initiative for application-to-person messaging in the US market. The main MNOs participating in 10DLC are AT&T, T-Mobile, and Verizon. With the recent Campaign Registry becoming mandatory, interest has spiked in A2P 10DLC.

If you're working on setting up your own messaging campaigns using A2P 10DLC, this guide will help you understand all the acronyms you'll see connected to this industry initiative. If you're not sure if 10DLC is the right choice of number for your use case, refer to our guide to choosing a number for your campaign.


A Mobile Network Operator - sometimes called a Mobile Carrier - is a company that provides mobile or cellular service on its own network of radio towers and switches.

If you’re familiar with the US market you’ll have heard of the three major MNOs: AT&T, T-Mobile, and Verizon. However there are also a handful of smaller MNOs like US Cellular and C-Spire.


Short Message Service and Multimedia Messaging Service are, respectively, text-based and multimedia messaging, and are defined by the mobile industry body GSM Association. 10DLC supports both SMS and MMS.


Although similar to the MNO in the respect that it provides mobile or cellular service, a Mobile Virtual Network Operator does not own or operate its own network of radio towers. Some MVNOs run their own switches, however. Instead, MVNOs lease capacity from an MNO. Examples include Mint Mobile (T-Mobile), Cricket Wireless (AT&T) and Boost (T-Mobile).

A2P and P2P

There are two types of SMS or MMS messaging - Person to Person, which is a person sending a message to another person using a mobile device, or Application to Person, which is an application sending a message to a person (or vice versa). Any message that isn’t sent from a mobile device by someone pushing buttons on a keypad is generally considered A2P.


The Campaign Registry is an organization that helps coordinate and manage 10DLC messaging campaigns. They work with CSPs, DCAs, the MNOs and third party vetting companies to ensure a brand is who they say they are, and the content being sent by that brand fits within the various messaging categories that the MNOs have defined.

Basically, TCR is a database that allows the carriers to see who is sending what, and how much they are sending, at all times. This transparency is meant to increase trust and reduce spam.

If you're new to the world of 10DLC and working through registering your first campaigns, you've come to the right place. At SignalWire, it's incredibly simple to register your brand and campaigns directly in your SignalWire Space using our TCR wizard.

We also have some guides to help walk you through filling out all the information needed for successful registration, like our beginner's guide to getting registered, and a list of tips from our expert carrier operations team to getting registered on your first try.


A Campaign Service Provider denotes an organization who has access to TCR’s portal and APIs to manage one or more 10DLC brands (and associated campaigns) on behalf of their customers or for themselves. SignalWire is a CSP, but we also work with customers who are their own CSP and use SignalWire as their connectivity partner.


A Direct Connect Aggregator connects to the MNOs and transmits SMS and MMS messages on behalf of its customers.


A Net Number ID is a six digit code assigned by NetNumber and used to identify which service provider is responsible for a particular telephone number.

In the world of 10DLC, the NNID helps the MNOs understand which DCA an A2P message is originating from or destined to.


In years past, Direct Inward Dial was a service which enabled a phone company to deliver a block of telephone numbers to a subscriber’s phone system (PBX) without requiring a separate physical line for each number. The term “DID” is still used today as shorthand for a telephone number.


A Mobile Station Integrated Services Digital Network is a way of identifying a unique mobile subscriber. In practical terms, an MSISDN is a telephone number formatted to the E.164 standard, so our earlier 10DLC example 2125552368 becomes +12125552368.

If you have any questions about 10DLC or registering a campaign, stop by our Community Slack or our Forum to connect with SignalWire's team of messaging experts! You can get started for free with our messaging platform free trial.

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