A telephone area code is a sequence of digits that you enter when dialing a telephone number in order to change the logical location.
A code consists of the traffic elimination number (VAZ) and the local area code (ONKZ).
This logical location usually corresponds to a geographical location for calls to the fixed network , a corresponding area code in the national number range is referred to as the local area code (ONKZ) , and corresponding subscriber numbers are so-called geographical numbers .
The logical location can also be a non-geographical number range (in Germany the phone code 032 ), an independent telephone network (e.g. mobile phone codes ), a service ( e.g. service numbers ) or a so-called "economy code" for the Act call-by-call procedure for the use of a specific network operator .
General information on history and necessity
Historically, telephone prefixes were created because telephone networks were only ever designed for limited locations. But as soon as two telephone networks have an at least partially overlapping number range, telephone numbers are no longer unique. They are often also used for routing (selecting the telephone network of a specific company) of a call. The international telephone prefixes have been standardized by the International Telecommunication Union (ITU) since 1964 .
Since then, the telephone area code in many countries has consisted of a traffic code and the actual area code. For example, if you want to make a call to Berlin within the German telephone network , you dial the sequence "030". The zero at the beginning is the traffic elimination number, the "30" the identifier for Berlin. For more information on the exact process, see under switching center .
For international telephone prefixes there is a different traffic elimination digit or (as an extension of the hierarchy) additional digits. In most countries this is "00"; the first digit then means "beyond the local level", the second "above the national level". In order to be able to uniformly note the resulting regional digit combinations, a “+” is also written for this, which is also used in cellular networks.
The situation of the telephone prefixes for IP telephony is somewhat more complicated and is described there.
There are different types of area codes:
- the international phone code to select the destination country, for example:
- +41 Switzerland
- +423 Liechtenstein
- +43 Austria
- +49 Germany
- in many countries the area code for selecting the logical telephone network within a country
- Mobile phone prefixes consisting of the national traffic elimination code, a network identifier and a block identifier depending on the country
Countries with mandatory use of the area code in all cases
In France (1996), Portugal (1999), Denmark , Norway , Italy , Belgium (July 2000), Switzerland (March 2002), the Czech Republic (September 22, 2002), Greece , Poland (December 5, 2005), Bulgaria ( March 10, 2011), Spain and Estonia have introduced the mandatory use of the area code, even if it is only a local call. One advantage of the method is that 11% more numbers are available per local network, as the number for special numbers (usually 1) or even the traffic elimination number (usually this is 0) are also used directly after the local area code can. Numbers that do not start with the traffic elimination number can also be used for special services and mobile telephony . Such a regulation is also a prerequisite for enabling the number portability of any subscriber number even when moving beyond local network borders, which has been implemented in Switzerland, Estonia, the Czech Republic and Luxembourg, for example ( see 032 numbers in Germany).
The implementation of the European Universal Service Directive 2002 and other efforts to porting or porting phone numbers (for mobile phones: Mobile Number Portability , MNP) limits the area code in its routing function, since the destination network is no longer fixed. This is a problem in particular for least cost routers , which should find the cheapest connection to the destination.
In Germany, a so-called fixed number (a number with an area code, i.e. practically all normal numbers in the fixed network) can only be assigned to subscribers who are actually located in the area of this number. Therefore, in Germany the porting of local phone numbers is only possible within the area of the local area code. However, this porting must be enabled when changing the provider ( TKG ).
International area codes, country codes
National area codes, numbering plans
German language area
- Democratic Republic of Congo
- Ivory Coast
- Sierra Leone
- United Kingdom
- North American numbering plan for USA, Canada, Caribbean states
|place||from the German telephone network||from the Swiss telephone network|
|Büsingen on the Upper Rhine||(+49) (0) 7734||(+41) (0) 52|
There are also two different postcodes .
- Structure and design of the number range for local network numbers ( memento of the original from September 24, 2015 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. (Vfg. 25/2006, Official Journal No. 7, Vfg. 18/2007; PDF; 122 kB) “With local network numbers, the ONKz allows conclusions to be drawn about the geographical location of the subscriber. [...] If the Federal Network Agency determines that a derived allocation has been made without considering the local network reference or that a local network number is still used despite the fact that the respective local network reference is no longer used, the Federal Network Agency orders the provider to deactivate the relevant number. "