The regulation of telephone numbers in Germany is the responsibility of the Federal Network Agency () of the German government. The agency has a mandate to telecommunications in Germany and other infrastructure systems.
Overview
Germany has an open telephone numbering plan. Before 2010, area codes and subscriber telephone numbers had no fixed size, meaning that some subscriber numbers may be as short as two digits. As a result, dialing sequences are generally of a variable length, except for some non-geographic area codes for which subscriber numbers use a fixed-length format. It is not possible to determine unambiguously the end of a phone number from a prefix or the digits already dialed. This feature allows the extension of the length of phone numbers without revoking or changing existing numbers. Mobile telephones are assigned to non-geographic codes, making them readily recognizable.
A new numbering plan was introduced on 3 May 2010. Since then newly assigned landline telephone numbers have a standard length of eleven digits, including the area code. Area codes remained unchanged, variable in length. Exceptions to the eleven-digit rule are the four cities of Berlin, Frankfurt, Hamburg, and Munich, which are the only cities with two-digit area codes and have ten-digit numbers to avoid exceeding the maximum length of eight digits for a subscriber number.
The German telephone network uses 5,200 geographical area codes, the length of which varies from two to five digits (not including the trunk code 0), with five-digit area codes being assigned only in the New States (prefix 3). In general, geographic area codes start with digits 2 to 9, whereas other non-geographic area codes (including those for cell phones) are assigned to 1 and network services to 11.
Geographic numbering
Geographic area codes have a length of two to five digits. The maximum length of a complete telephone number is eleven digits.
Numbers for geographic area codes are assigned to carriers in blocks. Subscriber numbers do not start with 0 or 11 and can be dialled without area code from landlines within the same geographic area code.
Originally, the first digits following the area code indicated a smaller service area or the type of the subscriber line (analogue or ISDN). This is no longer true as subscribers can keep their numbers when moving within an area code or when switching from analogue to ISDN. Furthermore, new carriers assign numbers from different blocks.
(xx) xxxx-xxxx
This is the format used for the four largest geographic areas in Germany: Berlin (30), Hamburg (40), Frankfurt (69) and Munich (89). Newly assigned numbers have a length of eight digits for the local subscriber number, yielding a total length of ten digits (not including the 0 trunk code). This is shorter than the maximum of eleven digits in other areas to avoid exceeding eight digits. Numbers assigned in the past, which are generally grandfathered, may be as short as five digits.
(xxx) xxxx-xxxx
In area codes of three digits, newly assigned numbers (for all locations from May 2010; earlier in some cities, e.g. Cologne in February 2007) also have eight digits, yielding a total of eleven digits. Grandfathered numbers may be as short as four digits (seven total).
(xxxx) xxx-xxxx
In area codes with four digits, newly assigned numbers (for all locations from May 2010, earlier in some cities, e.g. Heidelberg in May 2003) have seven digits, also yielding a total of eleven digits. Grandfathered numbers may be as short as three digits (seven total) in very rural areas.
(3xxxx) xx-xxxx
Some smaller areas in the former East Germany have five-digit area codes, all of which start with 3. Newly assigned numbers (for all locations from May 2010, earlier in some locations) have six digits, also yielding a total number length of eleven digits.
Non-geographic numbering
Non-geographic numbers were originally assigned the prefix 1. However, some of these services have been moved to other area codes.
10xy, 100yy
These numbers can be dialled before the telephone number to select a carrier.
11…
Area codes starting with 11 overlap the prefix for network services. In general, these numbers cannot be dialled from abroad, with the exception being 116xxx for harmonised services of social value.