Ask HN: Service exists, but not in my location

So, I had an idea for a start-up today, and in doing some research there's nothing that already exists in my geographic location (the UK) however there is a similar service based in the US.

Looking through the US site, they state they're only for US businesses - would it be better to talk to the US site and see if they'd be interested in expanding to the market I'm in, or execute the idea myself? Personally, I'd rather execute the idea in my own way, and as far as I can tell the idea doesn't involve anything patentable (and no, I wouldn't be looking to expand into the US market)