The +33 dialling code

The same number, formatted to be dialled from abroad.

33 is the telephone dialling code for France, allocated by the International Telecommunication Union. Preceded by a plus sign, it allows a French number to be dialled from any country, without needing to know the exit prefix specific to each territory.

In summary

33 is the international dialling code for France.
The 0 placed at the head of the national number drops after the dialling code.
06 12 34 56 78 is thus written +33 6 12 34 56 78.
This format, called E.164, is the one SMS gateways use.

The rule that troubles people most is the disappearance of the zero. This zero does not belong to the number: it is a national prefix, which tells the network that a long-distance call is being dialled within the country. From abroad, the +33 dialling code already fills that role, so keeping the zero would make the number invalid.

The full international format is called the E.164 standard. It accepts neither space, nor dot, nor dash: those separators exist only for human reading and are removed before any processing. It is in this form that SMS gateways, ours included, handle numbers behind the scenes.

For this site's form, however, the ten-digit national format is expected: the service only sends to French mobiles, and the conversion to international format is carried out for you, without revealing anything about your identity.