Telefonnumre

Telefonnumre are numeric identifiers used to identify a subscriber or service within a telecommunications network. They are assigned by national numbering authorities and are essential for routing voice calls, text messages, and other communications. International practice typically follows the ITU-T E.164 numbering plan, which limits numbers to a maximum of 15 digits and defines a structure of country code, national destination code, and subscriber number. In international notation, numbers are usually written with a leading plus sign, for example [phone].

Within a country, telefonnumre may include area or geographic codes, trunk prefixes, and special prefixes for mobile, non-geographic, or service numbers. Geographic numbers identify a region, while non-geographic numbers can route to mobile networks, VoIP services, toll-free lines, or premium-rate services. Short codes and service numbers are used for emergency services, customer support, or value-added services.

Dialing rules vary by country. Domestic calls use local or national formats, and international calls require an international access code followed by the country code and national number. Number portability is common in many countries, allowing a customer to keep the same number when changing providers within the same country.

Regulation and management: National regulatory authorities oversee numbering plans, allocation, and portability to ensure uniqueness and efficient use of the numbering resource. Privacy and abuse prevention are important considerations, with measures such as caller ID support, blocking options, and do-not-call regulations in many regions.