Personalize Your SMS Messages with an Alphanumeric Sender ID

February 12, 2020
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Increase open rates. Reinforce your brand. Improve message delivery. All with Personalized Alphanumeric Sender ID

Given the amount of spam and unwanted messages people receive on a given day, it’s no surprise they often ignore messages from an unfamiliar number. And if that message comes from an unfamiliar international number, the chances of a recipient opening it are particularly slim.

In countries that support Alphanumeric Sender IDs, leveraging them can dramatically increase your open rates. What’s more, for countries in which Alphanumeric Sender ID registration is enforced, you can also improve message delivery by reducing carrier filtering of A2P (application-to-person) traffic, as well as manage fluctuations in telecom logic, local regulations, and carrier-specific rules. When you register your Alphanumeric Sender ID, your messages and number are vetted with local authorities to establish the legitimacy of your messages and be passed through carrier firewalls.

And because you can send your SMS messages with a personalized sender name—such as your company name—your recipients will always know who is messaging them. That way you strengthen your brand every time you send a message that identifies your company.

You can use Alphanumeric Sender IDs only for one-way messages—recipients can’t respond. Because of this limitation, we recommend using Alphanumeric Sender IDs for one-way outbound messaging use cases, such as one-time passwords and account notifications. If you want users to respond, simply include contact information in your messages. Also, because users can't respond directly, we recommend including opt-out instructions in the message body to ensure compliance with CTIA and other regulatory guidelines, especially for promotional use cases. 

However, certain use cases for Alphanumeric Sender IDs are prohibited. Please review the full list here to ensure you have an approved use case.  

When to use Alphanumeric Sender ID

Alphanumeric Sender ID for supported countries is only available for upgraded (paid) Twilio accounts.

This feature works when sending single text messages, as well as when sending bulk messages through Twilio’s Messaging Service. Your Alphanumeric Sender ID will be selected automatically when sending to a supported country unless you have SMS-capable numbers from that country in your Messaging Service pool, in which case Twilio will use those numbers instead.

Note: You can still use an SMS-capable number to send SMS messages to countries that require pre-registration of Alphanumeric Sender IDs. However, delivery quality will be lower since these countries typically filter for A2P messaging traffic sent over long codes.


For most countries, using an Alphanumeric Sender ID costs the same as using a standard Twilio phone number. However, some countries, such as Russia and the Czech Republic, charge a monthly fee and/or a one-time set-up fee. For complete pricing information, go to Programmable SMS Pricing.

Are you ready to set up your custom Alphanumeric Sender ID? Here’s what you need to know.

OK, let’s get your Alphanumeric Sender ID  

In general, there are three steps to setting up your Sender ID. If the country to which you want to send personalized messages requires registration, you must also complete the registration process before you can set up your ID. An on-line form lets you register your Alphanumeric Sender ID and provides more information about any additional fees or restrictions for a given country.

1.   Ensure that the Alphanumeric Sender ID feature is enabled.

  •  Login to your project at
  • In the left-side navigation bar, click Programmable SMS.
  • Click Settings.
  • Verify that "Alphanumeric Sender ID" is set to Enabled.

2.   Check support for Alphanumeric Sender ID and registration requirements.

Go to International Support for Alphanumeric Sender ID and check the country list to see whether a particular country supports this feature—and whether registration is required.

If so, simply click on that country to display the form that will take you through all the fields required to register your Sender ID. For some countries, such as Indonesia and Vietnam, you’ll need to complete additional documents. You can download, complete, sign, and then upload these documents on the same form. Don’t fret—we provide you with detailed instructions for completing these documents for those countries that require them.

3.  Define your Alphanumeric Sender ID.

If the selected country does not require registration, define your ID according to the following requirements: Use up to 11 characters (except for India, which requires exactly six characters), including at least one letter. Non-ASCII special characters and punctuation are not allowed.

You can use:

  • Upper- and lower-case letters
  • Numbers 0-9
  • Spaces

Then simply enter the ID you defined into the From parameter of your API request, as shown in the cURL example below:

curl -XPOST \
-d "Body=Hello there" \
-d "To=+12685551234" \
-d "From=MyCompany" \

For full details, please see our Programmable SMS REST API documentation.

Reap the benefits

You’re now ready to enjoy all the benefits that come with using Twilio’s Alphanumeric Sender ID feature. Send messages from a personalized number that your users are more likely to receive—and open.

If you have any questions, please contact

Cliffton Lee is part of Twilio’s Product Operations Team and manages the day to day operations and processes for all things Alphanumeric Sender ID. helps social impact builders use digital technology and financial resources to scale their reach and impact. Get started today at no cost. Sign up here for your Impact Access Program product credits. Eligibility criteria applies.