One thing you need to take into consideration when going into these high interest accounts is the exchange rate which fluctuates constantly.
If you are exchanging currency to go into this type account and should you be going in with a view to exchanging currency back at any time then try to go in when the rates are in your favour. This gives you a better chance when exchanging back. Get the right rate at the time you exchange back and you could earn even more than the interest rates, but that’s the gamble.
Of course if you don’t ever expect to change back this does not apply but just for example the exchange rate for sterling today is 2.184 BGN so £1000 equals 2,184 BGN should the rate go to what they were 9th December 1.00 GBP = 2.251 BGN and you needed to change back to sterling you would only get back £970.00 less commission you would be charged on that exchange.