E.164 format, with examples

E.164 is the international format for phone numbers: a plus sign, the country code, then the number, with no spaces and at most 15 digits. A London number written in E.164 is +442079460018. The name comes from the ITU recommendation that defines it.

+exit code, any country44country code20area code, no 079460018subscriber number

Convert a number to E.164

Updated 10 November 2026.

E.164 format rules

Four rules turn any number into one format.

Starts with +

The plus stands for whatever exit code the caller's country uses. Written down, it makes the number work from anywhere.

1-3

Then the country code

One to three digits: 1 for the USA and Canada, 44 for the UK, 880 for Bangladesh.

Then the number, without the home prefix

Most countries add a trunk prefix such as 0 for calls at home. E.164 leaves it out, with a few exceptions.

No spaces, at most 15 digits

Digits only after the +, country code included. Spaces are for people; E.164 is for systems.

E.164 examples by country

The home prefix is where people get it wrong.

The same rule, drop what you dial only at home, gives different answers in different countries.

United KingdomDialled at home020 7946 0018E.164+442079460018Drop the 0.
United StatesDialled at home(212) 555-0123E.164+12125550123Add the 1, lose the brackets and dash.
ItalyDialled at home06 4567 8900E.164+390645678900Keep the 0: in Italy it is part of the number.
RussiaDialled at home8 495 123-45-67E.164+74951234567Drop the 8, Russia's home prefix.
HungaryDialled at home06 1 234 5678E.164+3612345678Drop the 06, Hungary's home prefix.

Every other country: paste the number into the international number formatter.

011

International dialling format

On a keypad, the + becomes your country's exit code.

E.164 is how a number is written and sent between systems. To dial it by hand from a landline, swap the + for the exit code of the country you are calling from.

Any mobile phone

Hold 0 for +. The network fills in the exit code for you.

Most of the world

The UK, Europe, India, Pakistan and most other countries dial 00 for +.

011

USA and Canada

The USA, Canada and the other North American plan members dial 011 for +.

So +442079460018 is dialled 00 44 20 7946 0018 from France and 011 44 20 7946 0018 from New York.

SIP

E.164 in SIP and phone systems

A SIP trunk routes by the full number. Leave out the country code and the call fails.

A trunk serves callers in many countries, so it cannot guess which country a local number belongs to. Send a national number and expect 404 Not Found or 484 Address Incomplete; the SIP troubleshooting guide covers both. Your phone system's dial rule should turn what people dial into E.164 before the call leaves: SIP trunk configuration.

The same London number, three ways a system writes it

E.164: +442079460018
tel URI: tel:+442079460018
SIP URI: sip:[email protected];user=phone

Storing phone numbers in E.164

Store one format. Show people another.

Keep the E.164 string as the record: text, not a number type, up to 16 characters with the +. Check it when it is entered, keep any extension in its own field, and format it with spaces only when you display it.

FAQ

E.164 questions

What is the correct format for a valid phone number?

For systems: E.164, a + followed by the country code and number, digits only, at most 15. For people: the same digits with spaces, such as +44 20 7946 0018.

Is E.164 written with or without the +?

With it. The standard defines the digits; the + in front is the agreed way to show that a country code follows. Some systems store the digits alone, but sending them without the + is a common cause of failed calls.

How many digits is an E.164 number?

At most 15, including the country code. The length below that varies by country and by number type.

What are the first 3 digits of a 7 digit phone number called?

In the USA and Canada, the exchange or central office code: in 555 0123 it is 555. The area code comes before it, making the 10 digits that follow the +1.

What does E.164 stand for?

Nothing beyond its place in the ITU's E series of telephone recommendations: it is recommendation number 164.

Got the number right? See what the call costs.

Per-minute rates by country, mobile and landline: international call rates. Why the same minute costs nothing on one service and dollars on another: how much an international call costs.

Format a list of numbers See call rates