Assuming Sweden is the same as Finland and Denmark then it's even better than the UK for not needing cash. The only DKK and EUR I need are for buying a bus ticket if I've forgotten my pass - and there's even an app for that.

In the UK I find that I need cash a couple of times a month, usually a market stall (most seem to use iZettle, but some don't). Occasionally you'll also get a cab trying to con you by saying their machine's broken - and suddenly getting it working again when you cite the law to them (they need a working card reader in London).