But you'll find it much easier to buy Canadian currency with your greenbacks at virtually any Canadian bank than it is for a Canadian trying to buy some US currency with Canadian money at a US bank. Two US banks in Lewiston, NY (a border town with a heavily used bridge to Canada) refused to exchange Canadian into US dollars unless "I had an account there". Now tell me, why would I have an account at a Lewiston, NY bank? We always go into the states with enough US dollars, but this time we ran out and the merchant didn't accept credit cards.