In 1999, Posten made considerable changes to the postal codes in Norway.
Since 18 March 1968 Norway has used a four-digit system: postnummersystemet.
The numbers start at 00 and increase with the distance from the capital city Oslo.
The highest post numbers are found in the county of Finnmark, near the Russian border, where they start with 95–99.
The first two numbers indicate the geographic location (counties) the postal code belongs to.