E.164 is the specification for a numeric telephone addressing scheme used by public switched telephone networks (PSTN) and various other data networks. E.164 numbers can address any phone connected to a (PSTN) in the world. Genesys Cloud converts E.164 numbers to other address formats in order for a caller to dial a number and call phones that belong to digital networks.
E.164 numbering follows these standards:
- An E.164-compliant telephone number can have a maximum of 15 digits.
- The first one, two, or three digits can represent the country code.
- The second part is the national destination code, or “NDC.”
- The last part is the subscriber number, or “SN.”
- The NDC and SN combined equals the national (significant) number.
- The combined length of the national (significant) number can’t exceed 15 minus the number of digits in the country code.
- E.164 is a number-only standard. Number range is 0-9.
Genesys Cloud normalizes an E.164 number by appending tel:+ to the beginning of the number.
North American numbering plan (NANP)
The NANP is a system of numbering plan areas (NPA) in the US, Canada, and the Caribbean.
The traditional formatting convention for NANP phone numbers is (NPA) NXX-XXXX, where:
- NPA is the area code
- NXX-XXXX is the subscriber number.
- The NXX prefix of the subscriber number indicates the local telephone exchange or rate center.