Calling a United States number from another country

From outside North America the pattern is exit code, then 1, then ten digits, and the leading 1 from the domestic format disappears.

The dialing pattern

From most of the world, a United States number is reached with three pieces: the international access code of the country you are calling from, the country code 1, and the ten digits of the number. Written out, that is exit code + 1 + NPA + NXX + XXXX. A customer in London dialing a New York number types 00 1 212 555 0142. A caller in Berlin types 00 1 415 555 0142. On a mobile phone the plus sign replaces the exit code, so the same number is stored as +1 212 555 0142.

Exit codes differ by country

The exit code, also called the international prefix, belongs to the country you are physically dialing from, not to the number you are calling. Most of Europe, much of Asia and Latin America use 00, sometimes followed by a carrier-selection code. The United States and Canada use 011. Australia uses 0011, Japan uses 010, and South Korea has several competing prefixes. Hotels and office systems often require a digit first to get an outside line, so a caller in a hotel may need to dial 9 before the exit code. Getting this step wrong is the most common reason an international call never leaves the building.

The number one is the country code

The 1 in +1 is not the long-distance 1 you dial at home. It is the country code of the North American Numbering Plan, shared by the United States, Canada and around twenty Caribbean countries and territories, Puerto Rico among them. Because it is a country code, it sits in the same position as 44 for the United Kingdom or 91 for India.

Drop the leading 1

Inside the United States, long-distance numbers are written as 1-212-555-0142. That first 1 is a trunk prefix: it tells the domestic network that a long-distance number follows. When you dial from abroad, the exit code already signals an international call, so the trunk 1 must be dropped. You dial exactly one 1 in total. Dialing 00 1 1 212 inserts a stray digit and the call cannot connect. The same rule applies in reverse: someone in London calling the United States drops the leading 1 from the American number, just as an American calling London drops the leading 0 from 020 7946 0958 and dials 00 44 20 7946 0958.

Common mistakes

• Dialing the domestic 1 twice: 011 1 1 415 555 0142.
• Using your home country's exit code while you are travelling in another country.
• Keeping a trunk zero before a foreign number, as if it were a local prefix.
• Omitting the country code and dialing ten digits, which works only inside North America.
• Storing numbers without the plus sign, then trying to call them from a foreign SIM card.

What will not work from abroad

Short codes are local by design. 911, 411, 511 and 988 reach services in the numbering plan you are standing in, not the one you are calling. Toll-free 800 numbers are also awkward: some are reachable from abroad through a special access number, many are not, and any call that does connect may be billed to you.

Before you dial

Check three things: the country code is 1, the next ten digits are the area code plus the number, and the number does not begin with 1. If the number you were given starts with 1, that 1 is the trunk prefix and is dropped from abroad.