I have actually looked into this (a little bit) because I was thinking about moving permanently to the UK....
Everything said above about doing residency abroad and returning to the US (Canada?) is true. You will likely have to repeat residency training in order to get licensed to practice here.
The UK's socialized medical system, the National Health Service (NHS), has a shortage of fully trained consultant (i.e. attending) doctors. Thus, in theory it should be relative easy for an attending physician to transfer from here to there IF already trained.
However, a couple of issues: 1) You're still required to undergo some (re)training in most cases IF you aren't trained in a European or British Commonwealth medical school,
and, with you needing to repeat at least some training, you need a training position in the UK, but
2) they have a HUGE bottleneck of foreign medical graduates (largely from India and Pakistan) who are seeking training (i.e. residency) positions, which are very few and far between.
The NHS needs more consultants than the numbers supplied by newly graduating "residents" (junior doctors / house officers). BUT... there is a huge number of people waiting for too few training (residency) positions. They don't need more residents, they just need more fully qualified physicians. # of training positions <<< # of people applying for them, with that huge influx of doctors from India.
There are barriers to "getting in" to the medical system in the UK if you didn't attend medical school there, just as there are in the US. A preference is granted to their own graduates, just as our system prefers our own. Despite the shortage of consultants in the NHS, most people are still required to repeat some residency training once they arrive in the UK, if they come from abroad. A few "high shortage" specialties (anaesthesia for sure, I think radiology and a couple others as well) are so short-staffed that you'll get more credit for previous training outside the UK than other specialties. So it partly depends on what you choose to go into.
Despite all of that, there is still a huge demand and I think it is supposed to go up, now that the UK is planning to limit their RESIDENT WORK HOURS to an upper limit of... I think.... 57 hours total! 😱 Wowsers. They are not likely to meet that goal any time soon because they don't have (tada) either enough doctors, or enough residents.
