I have several years of NYC bike messenger experience and I am wondering whether it is impossible for someone with no English back ground to get a job working in London for a courier company.
To expand on Bill's comment, if you have dual nationality then as an EU citizen you can work anywhere within the EU including Britain, If however you are 'only' a US citizen then you'll have the number of companies limited. If you come across now then your main problem will be that no companies are recruiting because work is VERY quiet and they have no need for new riders regardless of their provenance.
It is tough out there at the minute. Bad news is that it doesn't look like picking up any time soon. I'm gobsmacked at some of the wage packets that riders I know are picking-up, even at decent companies (Including Creative, Bill!) Averaging £30 for a day's work isn't uncommon at usually semi-respectable firms. I can't even make a living pedalling at the minute.....and you all know how incredibly popular I am in the industry. (Ahem!) After a couple of recent weeks of scraping £240, I've switched to a powered machine - something I only usually contemplate if it's really quiet in the summer. (I'm not so desperate that I'd contemplate going back to City Sprint. Yet. But I might be forced to try them if things don't pick-up soon.)
Companies usually inform their Fleet Managers and Recruitment Supremos to check ID and entitlement to work.....however, the bozos don't always do so. If you go in for the interview late on and then persuade the buggers to let you start early the next day, the a.m. bozo will often assume that you showed the ID and relevant docs the night before. In the last few years, I've started at Pink, Post Haste and CDS on motorbikes and not been asked for any ID at all. A bit of a shame that I lasted a combined total of about three months at them.
"Provenance", Gertie? You're getting a bit loquash....er...lokw....er.....flowery with the prose, aren't you? Anyone would think you've been out there since the days when intelligent people used to do the job.