From 01.01.2024, several counties will be divided, and we will have 15 counties in Norway.

Norwegian Parliament decided to divide the following counties:

Viken is divided into three new counties: Østfold, Akershus, and Buskerud.
Vestfold and Telemark are divided into two new counties: Vestfold and Telemark.
Troms and Finnmark are divided into two new counties: Troms and Finnmark.

(Note: Vestfold and Telemark, Troms and Finnmark they are being divided into themselves.)

As a result of that, when declaring in TVINN, the county of origin (column 34b) for export will also change.

The following codes of counties in TVINN will be discontinued:
-Viken (code 30)
-Vestfold and Telemark (code 38)
-Troms and Finnmark (code 54)

The following production counties will be added to TVINN:
-Østfold (code 31)
-Akershus (code 32)
-Buskerud (code 33)
-Vestfold (code 39)
-Telemark (code 40)
-Troms (code 55)
-Finnmark (Code 56)

source:
https://www.toll.no/no/verktoy/regelverk/nytt-fra-tolletaten/endring-i-opprinnelsesfylker-i-tvinn/