I've already got my offshore bank account, having been living on the IOM for the past 7 years. I plan on keeping it for a while to come yet as they are not that easy to open, so I'm not sure you could just "switch" your savings account from the UK to IOM without being resident here. I had to jump through hoops myself as an IOM resident just to open my regular account to have my salary paid into, and it's got a lot worse since.
Although all donations gratefully received
We're forever getting e-mails (spam) from across the world asking us to invest their money in our bank accounts, I could be rich by now, or in jail for money laundering
The interest rates here are pretty rubbish though, so although you may pay less in taxes you don't get as much in interest.
I'm not too sure on the legalities of this one as it's an absolute mine field, but what is also important is not where you are
resident, but where you are
domiciled. I learnt a little about that a while ago, and was told that if I had any account in the UK I would be liable for any Capital Gains/Inheritance Taxes as I would still be deemed to be "domiciled" there. So I closed all UK links - but it could be that a little knowledge is a dangerous thing when it comes to financial advising...
I would be interested to know how you get on switching UK accounts to an IOM based account.
Debby & Keith