Before Canada stopped using its penny, it was common to find American pennies in circulation.

It's still fairly common to find American nickels, quarters and dimes in circulation. (Probably mostly dimes if I had to guess.) They're generally accepted at par because nobody is even really looking at them and if they did it wouldn't really represent being, well, short-changed.

I’ve found that self-checkouts in Canada are a great way to get rid of piles of change. You can pretty much dump it in. Curiously, it will reject all the US coins and spit them back out.

Same in Britain (except that the rejection of US coins is ... less curious). The funny thing is that sometimes they have these strange machines nearby that I have never seen anyone using[1] but which claim to be able to convert coins for you while taking a cut.

It's true that not all the self-checkouts accept cash but if you go when it's not too busy you can easily find one that does.

[1] OK, I've occasionally "used" one myself but not for putting coins into it. I just like to cheer myself up by reading the hilarious list of objects that I shouldn't insert into it.

> Curiously, it will reject all the US coins and spit them back out.

I haven't found them to be noticeably less accepting of American coins than Canadian ones. (Small sample size; American coins in change definitely are less common than they used to be, although it does happen.)

Especially dimes. Man do they just not want to take any kind of ten-cent piece sometimes.