How to write a phone number in international format

The international format comes from ITU-T Recommendation E.164, the numbering plan every country follows. After the country code, the caller dials the national number "without dialling the national (trunk) prefix", which in most countries is a 0. ITU recommends the "+" symbol to show where the international prefix goes.

Organisations print their numbers in many ways: with dashes, with a 0 in brackets, with 00 in front. The international form underneath is always the same pattern.

A US number has a three-digit area code and a seven-digit number, and its country code is 1. Delta prints its International Sales & Service line as 800-241-4141; in international format that is +1 800 241 4141. A toll-free 1-800 number is written the same way as any other US number.

Writing it correctly does not make a toll-free number work from abroad: many US companies say their 1-800 numbers are for callers in the US and list other numbers for other countries. Our guide to calling US toll-free numbers from abroad covers that.

Not every 0 after the country code is a trunk prefix. GOV.UK puts its trunk 0 in brackets, +44 (0)191 218 3600, so you leave it out. Best Western prints its Milan number as +39 02 82953392, with no brackets, and here the 0 is part of the number. When a number is already printed with a plus sign, dial it as printed and leave out only a 0 in brackets.

We tested both forms of this one number on 21 October 2026, through Browzerphone's US phone provider from a US (+1) test number. With the 0, +39 02 8295 3392 connected to Best Western's menu. Without it, +39 2 8295 3392 failed straight away: the phone never rang.

The plus sign stands for the international prefix of the country you are calling from, so you can type that prefix instead. From the United States the FCC says to "dial 011, and then the code for the country you are calling", and its own example for mobiles uses the "+" sign instead. Elsewhere, use the international prefix of the country you are in; ITU recommends 00, and Marriott Vacation Club, for example, prints its Irish line as 00 353 21 730 4444.

Save every number with the plus sign and the country code. The entry then carries everything a call from another country needs, so you do not have to rewrite it when you travel.

Some websites want the number with no spaces, as in +18002414141. The digits are the same; E.164 caps the whole thing at 15 digits after the +, so a longer number has a mistake in it, most often an extra 0 after the country code.