Germany’s postal codes have been numeric and five digits long since 1993. Between 1990 and 1993, the previous four-digit codes in West Germany were prefixed with “W,” while those in East Germany were marked with “O” for “Ost” (meaning “east” in German). Although the western system had reserved certain number ranges for potential reunification, authorities opted to create an entirely new system in the 1990s. This allowed larger cities to be divided into multiple postal code areas and enabled companies receiving significant amounts of mail—such as mail-order businesses—to have their own dedicated postal codes. As a result, the size of a city could no longer be determined by the number of trailing zeros in its postal code, as had been the case before (e.g., Hamburg with 2000 or Munich with 8000).
Post office boxes are arranged in racks containing multiple individual boxes, each identified by a unique postal code.
The system introduced in 1993 incorporated geographic zones on two levels: the first level (Postleitzonen) and the second level (Postleitregion). For example, the number “1” represents Northeast Germany, while “10” designates a zone in central Berlin.
