US/UK English adaptation
As a Brit living in the United States, I hear this joke about once a week, and to be honest it's starting to wear á bit thin.
"What do you do for a living?"
"I'm a translator."
"What languages do you speak?"
"Blah, blah, blah."
"Do you translate American English to British English? Haha."
Well, actually I do, and there's a thriving market for it. There are huge differences between UK and US English, and despite having lived in this country for twelve years, I'm still learning them. It's not just the obvious things like lift/elevator and pavement/sidewalk either.
I still have to think ahead a sentence or two to make sure I don't say anything that will elicit a blank stare, like "I want a lie-in on Sunday" (I want to sleep late). I have to remember to keep my skeletons in the closet and not in the cupboard, to knock on wood rather than touching it, and to beat dead horses rather than flogging them. Where I live, a person who drives a train is not a train driver: they're a locomotive engineer.
So the differences are substantial, and they represent a potential pitfall for businesses. Americans reading British English often see variant spellings and vocabulary as inexplicable mistakes; British people may regard American English as arrogance and a failure to adapt to local markets.
So that's why I translate between UK and US English. Sometimes it's just a quick once-over, sometimes a fundamental rewrite. I work in both directions, and when I'm translating into US English I enlist the help of my American wife.
We also do brand-name consultancy, telling manufacturers and exporters whether their product and other names would work in our respective countries. Though there will always be some businesses that simply don't care: IKEA is one. I always grin when I see billboards for this local housebuilding company, and I wouldn't want to send my kids here either.