ITU-T E.164

The ITU E.164 standard defines the international numbering plan for telephony and related documents list the delegation (allocation of numbers) from this number space [ITU-T “List of ITU-T recommendation E.164 Assigned Country Codes”].

Note that in most countries only telecommunications operators are allocated blocks of numbers, while countries or regions are allocated their country/area prefix by the ITU.

Recommended maximum number of digits is 15. The format is typically:

Country Code (CC) - 1 to 3 digits
Identification Code (x) - 1 to 4 digits
Subscriber Number - 15 - (CC+x) digits

Slide Notes

ITU-T, “The international public telecommunication numbering plan”, International Telecommunication Union, Telecommunication Sector of ITU (ITU-T), Series E: Overall Network Operation, Telephone Service, Service operation, and Human Factors: International operation - Number plan of the internation telephone service, ITU-T E.164, February 2005

ITU-T, “List of ITU-T recommendation E.164 Assigned Country Codes”, International Telecommunication Union, Telecommunication Sector of ITU (ITU-T): Complement to ITU-T Recommendation E.164, Annex to ITU Operational Bulletin No. 835 – 1.V.2005, February 2005.

Transcript

[slide216] So that means we need to send and deal with the full E-164 numbers. So we have to specify the country code, et cetera. So the country codes were one to three digits, the identification code, the next field was one to four, and the rest was 15 minus the prefix. Except in Austria, which had 17. But just to make things more complex.