I hear from some people that when selling a large amount of Bitcoin and having that money hit their UK bank account, the bank has froze their money or notified them they will close their account.
Other people say they had no issues and no one has said anything.
Have you have any problems and more importantly who gave you the best rates and was the least hassle to deal with.
What you will have to deal with is the people in charge of the bank approving the money transfer. When they approve it, you have to make sure that you have enough money left over to pay for the tax...
Then you would have to note that in your yearly tax claim.
That's about it.