It is now a year since the new 100-krone and 200-krone banknotes were put into circulation. The old series of 100-krone and 200-krone notes will no`longer be legal tender after 30 May 2018.
While many banks and retailers will continue to accept old 100-krone and 200-krone banknotes, only Norges Bank will be obliged to accept them after 30 May 2018.
There are two alternatives for exchanging these banknotes after this date:
You can fill out a banknote exchange form and send both the form and the notes to Norges Bank. Norges Bank will transfer funds equal to the value of exchanged notes to the account indicated on the form.
You can exchange old 100-krone and 200-krone banknotes for new ones by contacting Norges Bank’s head office in Oslo or one of the Bank’s depots in Tromsø, Trondheim, Bergen and Stavanger. Since new banknotes will not be exchanged for amounts in excess of NOK 10 000, you must send or deliver the form and banknotes as specified above.
Source : norges-bank
