>do you have to be a company in the UK to get .co.uk?

No, my business has one and it is not a limited company

Actually, I meant more do you have to be in the UK to get .co.uk. Can you get that, or any other country specific address if you're in another country? Obviously, there's the famous complete purchase of Tuvalu's .tv domain by some corporation, but I'm not sure about the rules for other countries.