Telecom Utility
World Dialing Code & Area Lookup
Look up any country's international calling code, or reverse-search a code to identify the country — for clear, correctly formatted international calls.
Find a country's dialing code
United States
New York
United States
Los Angeles
United States
Chicago
Canada
Toronto
Mexico
Mexico City
Brazil
São Paulo
Argentina
Buenos Aires
United Kingdom
London
Reverse lookup: code → country
How international dialing actually works
An international phone call is built from three parts: an exit code (also called an international access code or IDD prefix), a country code, and the local subscriber number. The exit code tells your carrier you are leaving the country; the country code routes you to the right nation; the local number reaches the subscriber.
The plus sign (+) is a universal shorthand for 'whatever the local exit code is'. From a mobile phone, dialling +44 20 7946 0000 works from almost anywhere in the world because the handset translates the + into the correct exit code for the network you are on.
Exit codes around the world
Most of the world uses 00 as the exit code — it is the standard across Europe, much of Asia, Africa and South America. The United States and Canada use 011. Australia uses 0011. Japan uses 010. A handful of countries have idiosyncratic codes; when in doubt, the + symbol on a mobile sidesteps the question entirely.
Because exit codes vary, the country code alone is not enough to place a call from a landline — you must know the exit code of the country you are dialling from. This is why storing numbers in your contacts with the + and full country code is the safest habit: it works wherever you travel.
Shared country codes and the North American Numbering Plan
Country code +1 is shared by the United States, Canada, and many Caribbean nations under the North American Numbering Plan (NANP). Within NANP, a 10-digit number (3-digit area code + 7-digit subscriber) is dialled, and the area code distinguishes the country and region. This is why a call to Canada looks almost identical to a domestic US call.
Other shared codes exist too: +44 covers the UK and several British territories; +61 covers Australia and its external territories; the +590 code serves Guadeloupe, Saint Barthélemy and Saint Martin. Always check which territory a code reaches before assuming it maps to one country.
Why some codes are three digits
Country codes are assigned by the ITU in zones. Zone 1 is NANP, zone 2 is Africa (mostly two-digit codes like +20 Egypt, +27 South Africa), zones 3 and 4 are Europe (mostly two or three digits), and zones 5–9 cover the rest of the world. Three-digit codes are typically used where a two-digit code was unavailable.
Formatting numbers correctly
A correctly formatted international number has the country code, then the area or mobile prefix (with the leading trunk zero dropped), then the subscriber number. For example, a London landline 020 7946 0000 becomes +44 20 7946 0000; a Sydney mobile 0412 345 678 becomes +61 412 345 678.
Storing every contact in your phone in this international format means the number will dial correctly whether you are at home or abroad, and it avoids the common mistake of dialling a domestic number internationally with the trunk zero still attached — a call that simply will not connect.
Common mistakes and how to avoid them
The most frequent mistake is keeping the leading 0 in the local number when dialling internationally. The second is dialling a country code without an exit code from a landline. The third is assuming a country code maps to exactly one country — shared codes like +1 and +44 trip people up regularly.
A simple workflow avoids all three: store numbers with + and the country code, drop the trunk zero, and use the + symbol on mobile. When you must use a landline abroad, look up that country's exit code, then dial exit code + country code + local number (without the leading 0).
A short history of country codes
International dialing codes were standardised by the ITU in the 1960s as direct international dialling replaced operator-assisted calls. The zone system was designed so that a single leading digit would route a call to a broad region, simplifying early electromechanical switches.
Over time, codes have been split and reassigned as countries gained independence or demand outgrew capacity — for example, the Soviet Union's +7 now serves Russia and Kazakhstan, and Yugoslavia's +38 was split among several successor states. The codes in this tool reflect the current ITU assignments.
Frequently Asked Questions
What is an international dialing code?
An international dialing code (also called a country calling code or IDD code) is the numeric prefix you dial after your country's exit code to reach a specific country. For example, +44 reaches the United Kingdom and +81 reaches Japan.
What exit code do I dial first?
The exit code depends on the country you are calling from. Most countries use 00, the United States and Canada use 011, and Australia uses 0011. From a mobile phone you can usually substitute the + symbol for the exit code.
Why do some codes look the same, like +1 for the US and Canada?
The US and Canada share the North American Numbering Plan (NANP) under country code +1. They are distinguished by the three-digit area code that follows. Several other Caribbean nations also share +1.
Do I need to drop the leading zero of a local number?
Yes. When dialing internationally you drop the trunk prefix (the leading 0) of the local number. For example, a UK number 020 7946 0000 becomes +44 20 7946 0000.
Are area codes included here?
This tool focuses on country calling codes. National area codes vary widely and change over time; for a specific local area code, pair the country code here with an up-to-date national directory.
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