Payment methods in Sweden

Sweden is a highly cashless country. Most small businesses even small food truck vendors take money by electronic methods like cards. There is popular phone based app called "Swish". People use Swish money to friends family or even businesses. Even some online shopping sites have options to pay via swish.

Govt or private businesses take payments via "autogiro" or "bankgiro" which are two payment services offering a unique id for each biller. These are supported by all legal businesses and banks. And I think usually small payments are done by Swish.  Payments with invoices are done via autogiro/bankgiro. Amount is not a big consideration according to my understanding.

Some shops will take payments in Euro too.

And yes I haven't carried cash in Sweden since long time so definitely my habits have changed.

Yes as Faiz says it's a highly cashless country, how highly? According to the estimates of Central bank of Sweden they possibly might could achieve their goal towards a totally cashless society within 5 years. Even banks are now cashless, maybe only 1 out of 10-15 banks still has old fashion cash services.

Normally everyone pay their bills through internet banking. Almost all government related bills, rent, electricity bills etc. and many other serious private companies, banks, insurance companies etc and basically almost every bill you can get as an electronic bill direct to your internet bank and then all you have to do is log in to your internet bank and sign those bills. 

Other than swish there are other apps to pay car parking, for taxi, pizza etc and also to donate money for charity.   

Since Sweden is an EU country even though they voted down the Euro and kept Swedish Krona some traders (specially near the Finland border) try to be nice to the Euro but with some limitations, they don't like Euro coins and many don't accept over 50 Euro bills and you always get back Swedish Krona in change.

Answer to Priscillas second question is NO according to Swedish standard but some immigrant who owns a little convenience store type of grocery maybe rather makes a limitation like no card payments below 20 Kronor or something like that. 

About habits changing, yes dramatically, back then in Sri Lanka very few people used teller cards and the only bill we used to pay is the restaurant bill (when we occasionally  chose to go to a fancy place)