The E.164 stardard is an ITU-T (International Telecommunications Union) recomendation that aims to create a global numeric plan at world level.

The original documentation of can be acessed at ITU-T website, clicking here.

The telephone number in E.164 standard is preceded by the international call prefix (plus signal), by the country code (from 1 to 3 digits), by the area code (when used) and by the subscriber number.

A number in E.164 format must have at least 15 digits (without the prefix). Because it’s a standard that can be applied worldwide, VoIP Domain has choosed to use this standard in all public numbers in the system. At all reports and configurations, will be used this standard, even to local calls.

Below, an example number in the E.164 standard:

+55 51 992425885

Where, + is the prefix to international call, 55 is the code of Brazil, 51 is the area code of the state of Rio Grande do Sul and 992425885 is the subscriber number.

Through information from the ITU-T database provided by each country, we can have more information about the number, such as the area code and that this number is a mobile number (cell phone). A lot of information can be found in these documentations, which can be accessed here. VoIP Domain already has a database with information provided by ITU-T, and can provide more information on a number.

The system uses this information for billing, as many countries have different rates based on the type of dialed number, such as mobile phone, landline, satellite, among others.

The terms used by ITU-T for the E.164 standard are as follows:

  • CC: Country Code (from 1 to 3 digits)
  • NDC: National Destination Code (also known as area code)
  • N(S)N: National (Significant) Number (complete number excluding country code)
  • SN: Subscriber Number