Postal codes in the Faroe Islands consist of the two letter ISO 3166 code "FO", followed by three digits:
Separate postal codes are used for PO Box addresses, known in Faroese as postsmogur, in the capital Tórshavn and some other towns:
Previously, the Faroe Islands formed part of the Danish postcode system, introduced in 1967, which also included Greenland. This used the number range 3800 to 3899, and the "DK" prefix for Denmark:
Later on, the "FR" prefix was used:
When the three-digit postal codes were first introduced, they were used for PO Box addresses, alongside the existing four-digit ones.