What is E.164?

E.164 is an international phone number format recommended by the International Telecommunication Union (ITU). 

A phone number that follows the E.164 format ensures deliverability because each device on the Public Switched Telephone Network (PSTN) has a unique number. This means that calls and SMS can reach intended recipients internationally, so you can send SMS marketing messages to subscribers worldwide.

An E.164 number consists of up to 15 digits:

  1. Country code: The first digits identify the country or region (e.g., +1 for the United States, +44 for the United Kingdom).
  2. National destination code (NDC): These numbers represent an area or mobile network code within the country (e.g., 212 for New York City).
  3. Subscriber number: This is a unique number assigned to a person or a business.

An E.164 number is a string of digits without spaces, dashes, or parentheses. For example, a New York City number in this format would be +12125551234.

The plus sign (+) before the number means you don’t need to manually add an international dialing prefix like 00 or 011 when sending a text.

What role does E.164 have in SMS marketing?

E.164 simplifies national and global SMS marketing by providing a universal phone number format. It helps with:

  • Global reach: E.164 lets you send SMS worldwide using country codes. This means you can send special offers to subscribers in Australia (+61) or announce new products in Germany (+49).
  • Regional targeting: Within a country, E.164 helps you target specific areas using local codes. For example, you can send promotions to subscribers in New York City (212) to keep your messages relevant and localized.
  • Personalized campaigns: The format makes it easy to create tailored messages based on location, allowing you to send targeted discounts or holiday greetings to your subscribers.

A marketing automation platform like Klaviyo makes it easy to send SMS to international audiences. Import the phone numbers on your subscriber list to Klaviyo, segment the subscribers according to their location, and send them personalized SMS messages. Klaviyo easily fixes any typos and removes the extra symbols from your imported phone numbers, ensuring that they are all corrected to the E.164 format.

Sign up for Klaviyo today to optimize your SMS marketing efforts.

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