I wasn't specificaly recommending PwC. My point was really that all of the Big 4 will have personal tax teams, hopefully one of them at least will have an office convenient to where you are, and they will all have the international network to be able to get the answers you need.

My experience at PwC was, as I said, that the head of the personal tax team was always happy to have a preliminary talk with a new client for free, and then if more work needed doing to take it from there. I always thought that was quite a good way of doing it... I don't know how the others would play it.

I'm definitely not a personal tax specialist though, so I have no idea if there are more specialised small firms which would be able to give you the same sort of advice specifically relating to your circumstances. If you can find someone who is recommended and does know their stuff in this area then they will probably be cheaper than going to the Big 4, but I would personally prefer to have a Big 4 firm on the hook if the advice they gave me turned out not to be correct - much better odds of getting redress than with a small firm.