Numbers and routing
International prefix
The international prefix is the code dialled before a country code to leave the national network: 00 in France and most countries.
It belongs to the country you call from, not the one you call: 00 in Europe, 011 in North America, other values elsewhere. The plus sign in a number written in international format replaces it: it means 'the international prefix of the country you are in'. It is followed by the country code, then the national number without its leading zero.
Why it matters for fax
To fax France from abroad, dial the local prefix, then 33, then the number without the zero: a French fax machine on 01 23 45 67 89 is reached on 00 33 1 23 45 67 89 from Europe. The most common mistake is keeping the zero.