What the International Dialing Code Lookup does
This lookup gives you any country's calling code, its exit (international) prefix and its trunk prefix, and tells you exactly what to dial to reach a number in one country from another - plus the same number in E.164 format, the +country-code form that works from any mobile phone.
It works from a dated offline list: calling codes as assigned by the ITU in Recommendation E.164, with exit prefixes, trunk prefixes, example numbers and published number lengths taken from Google's open-source libphonenumber metadata. Nothing you type leaves your browser, and the list is not live - the page shows when it was last checked.
How to use it
- To find a code, type a country name, a two-letter ISO code such as DE, or a calling code such as +49 in the search box. The table lists every match with its exit prefix, trunk prefix, usual number lengths and an example number.
- To get dialling instructions, choose the country you are calling from and the country you are calling.
- Type the number the way it is written in that country, for example 020 7946 0958 for a London number. If the number already starts with + or 00, the destination is picked for you.
- Read the digits to dial, the E.164 form and the step-by-step explanation, then copy the E.164 number into your contacts.
Reading the results
The exit prefix is what you dial to leave your own country's network: 00 in most of the world, 011 in the United States and Canada, 0011 in Australia and 010 in Japan. Some countries publish several carrier-dependent exit codes; the page marks those as varying.
The trunk prefix, usually 0, is dialled only inside the country. It is dropped when calling from abroad, which is why 020 7946 0958 in London becomes +44 20 7946 0958. Italy is the well-known exception: its leading 0 on landlines is part of the number and stays.
The number length check compares the national number with the lengths published for that country. A mismatch usually means a missing or extra digit. A match only means the format is plausible - it does not prove the number exists.
Worked example: calling a London number from the United States
A business card shows 020 7946 0958. From the United States you dial the US exit prefix 011, then the UK country code 44, then the number without its trunk 0: 011 44 20 7946 0958.
The national number 2079460958 has 10 digits, and the UK list allows 9 or 10, so the length check passes. In E.164 it is written +442079460958. Saved that way in a phone's contacts, it works from the UK, the US or anywhere else.
The same number called from Australia would start 0011 44, and from India 00 44 - only the exit prefix changes.
Formulas and scoring rules
- International dialling
exit prefix of origin + country code of destination + national significant number- E.164
+ country code + national significant numberAt most 15 digits after the +, with no spaces or trunk prefix.- Within the North American Numbering Plan
1 + 10-digit numberCalls between the US, Canada and other +1 territories need no exit prefix.
Limitations: what the result does not prove
- The list is a dated snapshot. Numbering plans do change, so for a critical call check the destination operator's or regulator's published plan.
- Length checks come from published ranges. They cannot tell whether a number is allocated, in service or who owns it, and short codes, emergency numbers and premium numbers follow other rules.
- Some countries' exit codes depend on the carrier (Brazil and Colombia, for example). The page shows the published pattern, but your carrier decides.
- Letters in vanity numbers such as 1-800-FLOWERS are not converted; type the digits.
Privacy: where your data goes
Everything you paste, type or drop is processed in this browser tab. It is not uploaded, logged, stored or sent to analytics. Session recording and tag-manager scripts are switched off on this page.
Standards and sources
- ITU-T E.164 assigned country codes (List of ITU-T Recommendation E.164 assigned country codes) - checked 19 Sep 2026
- ITU-T Recommendation E.164 - The international public telecommunication numbering plan
- Google libphonenumber - phone number metadata (Apache License 2.0)
Frequently asked questions
What is the difference between a country code and an exit code?
The country code, such as 44 for the UK, identifies the country you are calling. The exit code, such as 011 from the US or 00 from most other countries, tells your own network that an international number follows. You need both unless you use +.
Can I use + instead of 00 or 011 when dialling abroad?
On a mobile phone, yes: the + tells the network to insert the right exit prefix for wherever you are. Many landlines and some office phone systems do not accept +, so dial the exit prefix there.
Why do I drop the first 0 when calling a number from abroad?
In most countries the leading 0 is a trunk prefix used only for calls inside the country. International callers replace it with the country code. Italy is an exception: landline numbers keep their 0 after +39.
What is E.164 format and why do apps ask for it?
E.164 is the ITU standard for international numbers: a +, the country code and the national number, with no spaces and at most 15 digits. Messaging apps, SMS services and CRMs store numbers this way so the same record works from any country.
Why do the United States and Canada share the code +1?
They are both part of the North American Numbering Plan, which also covers many Caribbean countries. Calls between them are dialled as 1 plus the ten-digit number, and the area code tells you which country the number is in.
Does this tool tell me whether a phone number is real?
No. It checks that the country code exists and that the number has a length that country publishes. Whether the number is assigned or switched on is known only to the network that owns it.
Last reviewed by the A2Z.Tools team against the sources listed above.
