What are they? I live in the US, not Canada, but the only word I can think of that is viewed more harshly in the UK than the US is “pissed”. Actually, that’s not quite true - TV networks that would bleep out “ass” (very mild in the UK) will happily have stereotypical English characters bloodying and buggering (if you know what I mean) all over the place. Not that “bloody” and “bugger” are terribly offensive in the UK, but you wouldn’t use them in “polite company”.
Fanny. As a lifeguard, I was issued a “fanny pack” to hold PPE, band aids, etc. The British girl could never call it that; it was always her “bum bag.”
That’s just a word with a different meaning - just as a Brit saying “fag” might cause offense in the US.
Isn’t that what you asked? A word that has an innocent meaning in the US which might raise eyebrows in the UK?
Fanny US= butt, rear-end, etc.
Fanny UK= pussy, cunt, etc.
Knock it off, already, guys.
Everyone knows the ‘No Sale’ key plays Duran Duran’s “Rio”.
I don’t think it was “Innocent Meaning” words but rather “Words which are swear words, but not particularly serious ones outside the US”.
For example, “Cunt” is the Tsar Bomb of Swear Words in the US. In Australia and the UK, it’s not something that should be used in front of one’s grandparents or in a professional environment, but it’s not really any worse than “Fuck”, and that one gets bandied about a lot here, I can assure you.
There’s a popular joke here in which the Holden Commodore, Ford Falcon, and Toyota Camry are known as “Clitoris Cars”. Why? Because every cunt’s got one. 
“Bugger” and “Bloody Hell!” are two of my favourite exclamations.
“Bugger!” works best when something has gone spectacularly wrong- but only if you act really nonplussed about it, as if the fact the rear axle has just fallen off the ute and the dog’s been crushed by a tree are all really minor inconveniences that will, at worst, necessitate a trip to Bunning’s the next time you’re in town.
Help me out here. What is the purpose of not having a No Sale button again? To annoy managers and piss off customers? And for what? So that it is infinitesimally less easy to steal from the cash register? If somebody wants to steal, I don’t see how making them buy a tootsie roll to open the register is going to stop them.
I don’t get it. Next time hire somebody you trust to be responsible for all the cash coming into the business, instead of a kleptomaniac ex-convict. And maybe you should pay them a little more, too.