E.164

e164.arpae164.orgcountry codeinternational telephone numbernational destination codeNational Significant Number (NSN)
E.164 is an ITU-T recommendation, titled The international public telecommunication numbering plan, that defines a numbering plan for the worldwide public switched telephone network (PSTN) and some other data networks.wikipedia
74 Related Articles

Telephone numbering plan

Area codeCalling codearea codes
E.164 is an ITU-T recommendation, titled The international public telecommunication numbering plan, that defines a numbering plan for the worldwide public switched telephone network (PSTN) and some other data networks.
The International Telecommunication Union (ITU) has established a comprehensive numbering plan, designated E.164, for uniform interoperability of the networks of its member state or regional administrations.

Public switched telephone network

PSTNtelephone networkpublic telephone network
E.164 is an ITU-T recommendation, titled The international public telecommunication numbering plan, that defines a numbering plan for the worldwide public switched telephone network (PSTN) and some other data networks. E.163 was the former ITU-T recommendation for describing telephone numbers for the public switched telephone network (PSTN).
The E.163 and E.164 standards provide a single global address space for telephone numbers.

Telephone number

phone numbertelephone numbersphone numbers
E.164 defines a general format for international telephone numbers.
In the international telephone network, the format of telephone numbers is standardized by ITU-T recommendation E.164.

ITU-T

CCITTTelecommunication Standardization SectorComité Consultatif International Téléphonique et Télégraphique
E.164 is an ITU-T recommendation, titled The international public telecommunication numbering plan, that defines a numbering plan for the worldwide public switched telephone network (PSTN) and some other data networks. E.163 was the former ITU-T recommendation for describing telephone numbers for the public switched telephone network (PSTN).
Public telecommunication numbering plan, E.164

Telephone number mapping

ENUME.164 Number Mapping
E.164 numbers may be used in the Domain Name System (DNS) of the Internet in which the second-level domain e164.arpa has been reserved for telephone number mapping (ENUM).
Internationally, telephone numbers are systematically organized by the E.164 standard, while the Internet uses the Domain Name System (DNS) for linking domain names to IP addresses and other resource information.

SIP URI scheme

When a number is mapped, a DNS query may be used to locate the service facilities on the Internet that accept and process telephone calls to the owner of record of the number, using, for example, the Session Initiation Protocol (SIP), a call-signaling VoIP protocol whose SIP addresses are similar in format (user@domain...) to e-mail addresses.
Such a number could be a private branch exchange or an E.164 telephone number dialled through a specific gateway.

Voice over IP

VoIPvoice over Internet Protocolvoice-over-IP
When a number is mapped, a DNS query may be used to locate the service facilities on the Internet that accept and process telephone calls to the owner of record of the number, using, for example, the Session Initiation Protocol (SIP), a call-signaling VoIP protocol whose SIP addresses are similar in format (user@domain...) to e-mail addresses.
E.164 is a global FGFnumbering standard for both the PSTN and PLMN.

List of country calling codes

Country CodeDialing codeTelephone code
The presentation of a number at the B-party device is usually prefixed with the plus sign, indicating that the number includes the country calling code.
They are defined by the ITU-T in standards E.123 and E.164.

ITPCS

+991XC
This recommendation contains the criteria and procedures for an applicant to be temporarily assigned a three-digit identification code within the shared E.164 country code +991 for the purpose of conducting an international non-commercial trial.
Application templates addressed to the ITU for E.164 shared country codes and identification codes require descriptions of the "Public Correspondence Service" to be provided with those codes.

Carrier of Record

Carrier of Record
Carrier of Record (or COR), refers to the entity that provides PSTN service for an E.164 number.

Telecommunications network

networkcommunication networkcommunications network
E.164 is an ITU-T recommendation, titled The international public telecommunication numbering plan, that defines a numbering plan for the worldwide public switched telephone network (PSTN) and some other data networks.

Plus and minus signs

minus signplus sign+
The presentation of a number at the B-party device is usually prefixed with the plus sign, indicating that the number includes the country calling code.

Trunk prefix

trunk code8city or region
When dialing, the number must typically be prefixed with the appropriate international call prefix (in place of the plus sign), which is a trunk code to reach an international circuit from within the country of call origination.

Telecommunication

telecommunicationscommunicationstelecom
The E.164 recommendation provides the telephone number structure and functionality for three categories of telephone numbers used in international public telecommunication:

Routing

network routingroutedroute
For each of the categories, it details the components of the numbering structure and the digit analysis required for successful routing of calls.

Integrated Services Digital Network

ISDN ISDNISDN30
Annex B provides information on network identification, service parameters, calling/connected line identity, dialing procedures, and addressing for Geographic-based ISDN calls.

List of international call prefixes

International call prefixinternational access code+
Plan-conforming numbers are limited to a maximum of 15 digits, excluding the international call prefix.

Telephone

phonetelephonesLocal Telephone Service
E.163 was the former ITU-T recommendation for describing telephone numbers for the public switched telephone network (PSTN).

United States

American🇺🇸U.S.
In the United States, this was formerly referred to as a directory number.

Criterion

criteria
This recommendation describes the procedures and criteria for the reservation, assignment, and reclamation of E.164 country codes and associated identification code (IC) assignments.

Internet

onlinethe Internetweb
E.164 numbers may be used in the Domain Name System (DNS) of the Internet in which the second-level domain e164.arpa has been reserved for telephone number mapping (ENUM). Some national telephone administrations and telephone companies have implemented an Internet-based database for their numbering spaces.

Domain Name System

DNSresource recorddomain
E.164 numbers may be used in the Domain Name System (DNS) of the Internet in which the second-level domain e164.arpa has been reserved for telephone number mapping (ENUM).

Domain name

domaindomain namesdomains
In the system, any phone number may be mapped into a domain name using a reverse sequence of subdomains for each digit.

Session Initiation Protocol

SIPSession Initiation Protocol (SIP)SIP Trunking
When a number is mapped, a DNS query may be used to locate the service facilities on the Internet that accept and process telephone calls to the owner of record of the number, using, for example, the Session Initiation Protocol (SIP), a call-signaling VoIP protocol whose SIP addresses are similar in format (user@domain...) to e-mail addresses.