The ‘0’ in a phone number is called a ‘trunk prefix’ – it is used to notify the circuits of the telephone network that the number being called is in another region of the country.
It is similar in function to a leading ‘1’ that is used within the North American Numbering Plan (NANP).
On this page
- Where a leading ‘0’ is found
- Dialing within the same country / region
- Dialing from outside the country / region
- Mongolia and Hungary
Where a leading ‘0’ is found
A leading ‘0’ is very common in Europe, Asia, Australia, and New Zealand.
It is found sporadically across African and South American countries.
Hungary uses ’06’ and Mongolia uses ’01’ or ’02’ as a trunk prefix – advice for calling within and to these countries can be found on their respective calling pages.
Dialing within the same country / region
… long distance
When dialing within the same country, the usual rule is that a leading ‘0’ is used when calling long distance or when calling to a difference regional code.
Long distance calls are usually billed at a higher rate than calls to local numbers.
Specific dialing rules can very greatly across countries.
When dialing locally (within the same area or geographic code) the general rule is that the leading ‘0’ and the area code are not part of the calling sequence.
Local calls are usually billed at a lower rate (or included in a flat rate) than calls to long distance numbers.
Specific dialing rules can vary greatly across countries.
… mobile phones
Some countries have separate area (geographic) codes for mobile phones. When calling between a mobile phone and a landline, the leading ‘0’ and geographic codes are usually included in the dialing sequence.
Dialing from outside the country / region
… it is dropped most of the time
When dialing to a country with a leading ‘0’, most of the time the leading ‘0’ is dropped from the call sequence.
The Louvre Museum in Paris, France lists its phone number in Paris as +33 (0) 1 40 20 53 17.
If this number was dialed from London, United Kingdom, it would be dialed:
|00||33||1||40 20 53 17|
|exit code from the UK||country code for France||geographic code for Paris||local phone number within Paris|
In this case, the leading ‘0’ is dropped as it would only be used as a long distance trunk number when calling across France.
… it is modified some of the time for calls to: Hungary
International calls to Hungary have a leading ’06’ dropped from the call sequence.
… it is not dropped for calls to: Italy, San Marino, Vatican City, the Ivory Coast, Rwanda, and the Republic of the Congo (but not the Democratic Republic of the Congo)
When calling to these countries, the leading ‘0’ should be included in the call sequence.
The Ivory Coast uses a leading ‘0’ for mobile phone numbers. The leading ‘0’ is included in the call sequence.
Rwanda uses a leading ‘0’ as a designation for satellite phone numbers in the country. It is included in the call sequence.
The Republic of the Congo uses a leading ‘0’ as a designation for mobile phones in the country. It is included in the call sequence.
Mongolia and Hungary
In both these countries, the entire trunk prefix is dropped from the call when the call is dialed from outside the country.