Norway
Operation of the single window
Regarding Article 10.4.3 on notification of single window, Norway operates:
TVINN for import and export declaration and collection of statistics:
https://www.toll.no/en/corporate/import/declaration-of-goods-into-norway/declaration-using-tvinn/
Safe Sea Net for maritime traffic:
https://www.kystverket.no/en/sea-transport-and-ports/safeseanet-norway/about-safeseanet-norway/
AltInn is the main portal for contact between citizens and governmental agencies, including border agencies:
https://altinn.no/en