What is an SMS sending number?

An SMS sending number, or a sender ID, is a phone number used to send SMS or MMS messages to subscribers who have consented to receive them. 

Sending numbers are vital for properly identifying your brand as a sender, which is necessary for compliance with regulations. But the type of sending number you choose will depend on your needs, namely how much volume you want to send, how much you want to pay, and how concerned you are with filtering.

Types of sending numbers

  • Long code: The standard 10-digit phone number that follows the North American Numbering Plan, typically used for person-to-person messaging.
  • Short code: A shorter, 5- or 6-digit number for sending high-volume marketing messages, alerts, and notifications.
  • Toll-free number: A phone number starting with a specific code, like 0800, 800, or 1800, that allows customers to text a business about products or services for free.
  • Branded sender ID: A customised alphanumeric sender ID with a brand name or company name to increase brand recognition.

How to choose the right sending number for SMS marketing

When you’re deciding on what type of sending number is right for your brand, consider the following:

  1. Location: Where are most of your subscribers located? Depending on the country you’re sending to, you may have access to one or more types of sending numbers. Here’s an availability chart for reference.
  2. SMS list size: If it’s available in your region and you send SMS campaigns to more than 30,000 people, you may want to get a short code. If you’re sending to fewer people, a toll-free number may be a better option.
  3. Two-way versus one-way: If you’re sending SMS in the UK or Ireland, for example, you’ll be able to use a branded sender ID for two-way SMS. In other regions, however, branded sender IDs don’t support two-way SMS.

Ready to get the right sending number for your brand? Sign up for Klaviyo, a marketing automation platform platform that makes it easy to apply for short codes and toll-free numbers, so you can start to generate revenue with SMS campaigns.

Additional resources