What is E.164?

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

Each device on the public switched telephone network (PSTN) has a unique number.

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. Area code: These numbers represent an area or mobile network code within the country (e.g., 212 for New York City). Note that this is also called a “dialing code” in some regions.
  3. Local phone 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.

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).

A marketing automation platform like Klaviyo makes it easy to send SMS messages to international audiences. Import the phone numbers on your subscriber list to Klaviyo, segment them according to their location, and send them geo-targeted SMS messages. Klaviyo removes any extra symbols, letters, or spaces from your phone numbers to be in the E.164 format.

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

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