I just read an interesting post about US versus UK English by Jill Sommer (@bonnjill on her blog Musings from an overworked translator. Jill explains why she declines requests to translate into UK English and how simply changing the spelling of certain words doesn't turn a text into UK English. The comments section for that post features a spirited discussion about how different the two "Englishes" really are.
Like Jill I am sometimes asked to translate into UK English and i generally decline. However, in technical writing at least, a somewhat hybrid form of English seems to be emerging. When I explain to clients that living in the U.S. I don't feel comfortable enough with British English to translate into that variety of English, I am sometimes told that proper UK English is not what they're looking for anyway. Rather, they want a non-country-specific "global English" with British spelling.
Well, I can (and have done) that. Such a hybrid form wouldn't work for legal texts, where not only the text, but the legal system itself needs to be translated. But in my specialty, IT, most terms were coined in the US to begin with. And frequently the translation I provide is not really - or not exclusively - intended for the UK market anyway. Rather, specifications, data sheets and similar materials are translated into English as a lingua franca. UK spelling is requested because that is the spelling most Europeans learn in school. As long as my clients are clear about the fact that my terminology and style will be based on US, not UK, English, I'm happy to run the finished translation through whichever spell checker they prefer.
Other clients (agencies) have said that providing a US English translation for what will eventually be delivered to a UK end client is okay because they will have a UK proofreader/editor change it to conform to British English. Conversely, I have been asked to "Americanize" a translation done by a UK translator so that it can be delivered to a US end client. If the agency knows that the editor will need to change quite a bit to adjust for the other variety of English, they won't fault the original translator for "poor quality", and everyone is happy.
So while I don't accept work that specifically calls for UK English, some of these workarounds allow us to exploit time differences across the Atlantic, as well as provide the internationalized English many end clients are really looking for.