You need to be a non-dom to be make use of the remittance system and not be liable to tax upon the sale of your asset (in this case Bitcoin or other crypto).

Most former British colonies have a similar system (in particular, Ireland, Malta and Cyprus) and (if you have a British passport) could make use of the system there, as you do not have your domicile in those countries.

See http://www.telegraph.co.uk/finance/personalfinance/expat-mon...

Ok non-dom but it comes with some strings attached. I understand you must pay £30,000 per year and the proceeds of the sale of the btc must never be repatriated to the UK.

Fee does not apply in the first 7 years. You could move to the UK for one tax year, and then move to Sweden, taking your money with you. You would have booked your entire gain tax free since it was "taxed" in the UK.

Or you could move to Malta for a tax year, and then move to the UK. It would be tax free as well. In my view worth doing if it's a sizeable sum.