Indeed if you are not yet a citizen of UK it's probably more complicated (I have no idea), and you might have to pay taxes... but I'm not an expert (at all). There are probably many other countries that have a trade agreement with the States in order to pay no/low taxes (Europe, maybe Autralia?).
At least if you live in UK you already have an advantage on me: you can more easily understand/speak oral English than I do, which will make the process to retrieve the EIN much faster (--> apply by phone). You can probably explain your situation to the IRS directly.
There is also a service to apply to the EIN online but it's only for US residents.
If you want an EIN - not by phone - you'll have to fill a W8-ben form:http://www.irs.gov/pub/irs-pdf/fw8ben.pdf
(even if you plan to apply by phone, it's always good to be ready to reply the answers, and the questions will be based on this form)
You can find all the instructions on the site of the IRS: http://www.irs.gov/Businesses/Small-Businesses-&-Self-Employ...
From my own experience it has been very challenging to retrieve this number, because of a lack of informations for foreign people, the fact that I am an individual worker, and some mistakes I made in the W8 form. I hope you'll succeed faster than I did!