10DLC Numbers

This article walks you through what a 10DLC is, why it matters, and how to register the right way. If you're sending SMS messages using U.S. long codes (10-digit numbers), 10DLC registration isn’t optional - it’s essential. Mobile carriers require that all business messaging traffic over 10DLC be registered for transparency and compliance. 

If you already know what a 10DLC is and want to get started setting one up you can jump ahead to the relevant sections of this article:

• Option 1: Purchase one of our dedicated 10DLC numbers
• Option 2: Bring your existing virtual or landline 10DLC number and text-enable with us
• How to register your 10DLC Number

What is a 10DLC?

10DLC stands for 10-digit long code - a type of phone number used for person-to-person communication that has been approved for business use. Carriers like Verizon, T-Mobile, and AT&T now require businesses to register these numbers and their messaging use cases before sending traffic. Registration is intended to reduce spam, protect consumers, and improve overall trust in messaging channels.

Why registration is required

As of 2023, if you’re sending SMS from a 10DLC number in the U.S., here’s what’s required:

✅ Your brand must be registered.

✅ Each campaign use case (e.g. marketing, alerts) must be declared and approved.

✅ All long code numbers must be linked to a registered campaign.

Failure to register can result in:

• Messages getting filtered or blocked
• Fines or penalties from carriers
• Suspension of your 10DLC service

How to obtain a 10DLC Number

There are two ways to obtain a 10DLC number to use with Sinch Engage:

Option 1: Purchase one of our dedicated 10DLC numbers

1. Log in to the Sinch Engage platform
2. Go to Settings > Numbers

3. Add a dedicated number

   

4. Select United States from the Country dropdown menu, choose a number and click Add dedicated number.

   

Option 2: Bring your existing virtual or landline 10DLC number and text-enable with us

If you already have a virtual number or landline 10-digit-long code number, you can bring it to Sinch Engage,

1. Log in to the Sinch Engage platform
2. Go to Settings > Numbers 

3. In the Own numbers section, click Add Number

   

4. Enter the number you want to bring in for text-enabling and accept the disclaimer
   Naming the number is optional and will not be seen by contacts (recipients) 

   

5. Upload proof of ownership by attaching a file showing that this number belongs to your business, like a billing statement from your phone provider or a screenshot of your account dashboard with your business name
6. Click Continue

If you have previously done a 10DLC registration, our team will text-enable the number and if a new 10DLC registration required, you will be prompt to become a registered sender. 

How to register your 10DLC Number

Whether you brought your own number or purchased one from us, you'll need to complete the 10DLC registration process if it hasn't been done already.

1. When adding a new number (either your own or a purchased one), the registration workflow will begin automatically. Click Begin Registration Process 

   

2. Once you have your EIN and legal company name ready click Continue to go to the next step.

   

3. Enter a description of the messaging use case(s) you will use the number for, and provide sample message content. This is used by the mobile carriers to help ensure that spam messages aren't sent using the number.

   

4. Enter details of how your recipients will opt-in to receive messages from you. If they will opt-in via keyword, you must provide the keyword(s) that will be used. Additionally, you must indicate how many messages each of your subscribed recipients will typically receive in a month, and indicate if you will be sending messages relating to financial services and/or age gated topics (alcohol, tobacco, etc). 

   

5. Enter the details of your organization. This will be used during the registration process to ensure the legitimacy of all businesses attempting to send messages using local numbers in the United Sates.
    

   

   

6. Once you finish entering all of the information for your number registration, review the details to confirm that everything is correct. If so click on Submit. 

   

   Your registration request will then be processed and you will be notified via email as soon as it is verified and the number is ready to use.

Key 10DLC campaign types

Your use case defines how your traffic is categorized and approved. Examples:

• Customer care - order updates, appointment reminders, account notifications
• Marketing/promotions - discounts, new product alerts (requires clear opt-in)
• Account security - 2FA, password resets, fraud alerts

Some types of messaging, such as SHAFT content (sex, hate, alcohol, firearms, tobacco), are strictly prohibited.

Compliance essentials

To ensure your 10DLC campaigns stay compliant and deliverable, follow these best practices:

• Get opt-in: Users must consent to receive your messages before you send anything.
• Include brand identification: Your brand name should appear in the first message.
• Enable opt-out: Include instructions in every message (e.g., "Reply STOP to unsubscribe").
• Avoid public link shorteners: Use branded URLs or full domain links to avoid flagging.
• Avoid all caps: Messages written in all caps may be filtered or flagged as spam.
• Use appropriate messaging frequency: Avoid sending too frequently or without value - both are major reasons users unsubscribe.

Carrier requirements at a glance

Gmail & Yahoo-style standards apply here too. Just like inbox placement depends on sender reputation in email, your SMS messages will be filtered based on:

• Complaint rates (keep below 0.1%)
• Opt-out handling (unsubscribe requests must be honoured within 2 days)
• Authentication and transparency (your brand must be clearly identified)