The instant access savings account reward (IASA Reward) offers a fixed rate of up to 6.35% AER for one year on balances between GBP100,000 and GBP1 million. Other rates for lower balances start at 6% AER on GBP5,000.

Other features of the account include an allowance of up to four withdrawals and unlimited deposits up to GBP1 million until December 31, 2007. In addition, the account can be managed around the clock by telephone, online, post or by optional cash card.

After one year, or if the above requirements are not met, the account reverts to the standard instant access savings account with variable interest rates.

Mike Regnier, head of savings at Bank of Scotland, said: Our latest IASA Reward offers a cracking rate of interest that is guaranteed, and still gives our customers the flexibility to access their savings if they need to. Few providers offer this type of deal so we’re delighted to offer a great account that meets savers’ needs.