E.164 format

E.164 defines a format for international telephone numbers. Numbers are usually prefixed with the plus sign (+), include the international country calling code and are limited to a maximum of 15 digits.

Phone numbers include:

• a + sign to indicate that the number is international
• a country code, such as 44
• a region code, such as 1234 (remove any leading digits, usually a zero, if applicable)
• the subscriber number, such as 567890

Example telephone numbers in national and E.164 format