Moreover, you most likely wonโt have any troubles whatsoever when paying for things in Norway with Visa and MasterCard while American Express is not so popular in both
Norway and
Scandinavia in general. Anyway, if you have any doubts, you can always ask an assistant before starting your shopping.
Plus, it is recommendable to check with your bank back at home before you begin your travel to find out if there will be any additional bank fees for charges made in a currency that is different from yours, for example, for payments made in Norwegian Krone to USD.