Postal codes in Denmark are determined by a four digit system that was introduced in 1967.

Note : Source : https://en.wikipedia.org/wiki/Postal_codes_in_Denmark

Postal codes in Denmark are determined by a four digit system that was introduced in 1967.[1] The only exceptions are five special purpose 3-digit codes. The self-governing territory of Greenland[2] is part of the Danish system (39xx). Historically, the Faroe Islands also formed part of the Danish postal code system using the 38xx range and the prefix "FR", but this was changed to a new format consisting of a three-digit code and the country code "FO", with FR 3800 Tórshavn becoming FO-110 Tórshavn.[3] New regulations add the country code DK to the postal codes, but in practice it is most often omitted. The code is written before the city name. Examples: 1000 København C (Copenhagen City) 6100 Haderslev DK-9000 Aalborg Ministry of Foreign Affairs of Denmark Asiatisk Plads 2 DK-1448 Copenhagen K or in Danish Udenrigsministeriet Asiatisk Plads 2 1448 København K - not necessarily with the DK - Be aware that the DK or Denmark must be used when mailed from abroad.