9.3. Telephone numbers
The ways of writing telephone numbers are controlled by various international standards issued by the International Telecommunication Union (principally recommendations ITU-T E.122, E.123 and E.126).
In practice, however, these norms pose various difficulties, especially those concerning the recommended forms of presentation. For reasons of simplification, the EU authorities have agreed on a uniform presentation in all EU languages, according to the following principles.
+33 140633900
+32 222020-43657
Grouped telephone numbers
When indicating more than one telephone number, separate them using a forward slash with a space either side:
+33 140633900 / 140678900 / 140123456
When indicating consecutive numbers in an abbreviated manner, use a forward slash without spaces. Use a hyphen to indicate the start of the variable part of the phone numbers, in the same manner as for extension numbers (see fourth bullet point above):
+33 1406339-00/01/02
Abbreviations/symbols
Introductory expressions
The following expressions are generally used to introduce contact numbers:
Alternatively, a graphic symbol may be used:
☎ +33 1406339-00/01/02
In order to make it easy to remember, the Europe Direct telephone number is an exception to the above rules and should be written as follows:
00 800 6 7 8 9 10 11