E.164 format
E.164 is the international phone number format: a plus sign, the country code and the national number with no spaces, up to 15 digits, e.g. +14155552671.
What is E.164 format?
E.164 is the international phone number format: a plus sign, the country code and the national number with no spaces, up to 15 digits, e.g. +14155552671.
Why you should use it
APIs and most sign-up forms expect E.164. Typing a number with the wrong country code is the most common reason a code never arrives.