Savers scouring the market for the best deals should remember that appearances can be deceptive. Many of the highest rates are bolstered by bonuses that will fade away after six to twelve months, leaving rates that are considerably less attractive.

For example, Scottish Widows pays 4.91 per cent on its no-notice account for deposits between £10,000 and £20,000. After six months this drops to an unimpressive 4.16 per cent. Savers depositing £10,000 will earn £40.91 a month for the first six months and £34.66 a month thereafter, leaving them £38 worse off after a further six months. Northern Rock’s no-notice account falls by 0.71 of a percentage point after six months, from 5.01 per cent to 4.3 per cent.

Rachel Thrussell, of Moneyfacts, says: “People will really feel the loss of half a percentage point or more, and many accounts offer at least that much of a bonus.”

Not all bonus accounts are bad news for lazy savers. Capital One’s Easy Access Savings pays 4.75 per cent, including a quarter-point bonus. When the 12-month introductory period ends, customers can coast along with a respectable 4.5 per cent. Heritable Bank’s 90-day notice account pays 4.9 per cent for six months before dropping to 4.5 per cent.

Those who want a decent rate without the complication of a bonus period might consider a straightforward instant-access account.

Anglo Irish Bank pays a meaty 4.8 per cent without a bonus, while Mansfield Building Society pays 4.75 per cent on its Postal Tracker.

“Savers looking for a no-frills place for their money to grow can always look to building societies,” Ms Thrussell says. “Because they are not seeking to please shareholders, mutuals such as Yorkshire, Nationwide and Britannia tend to offer better rates, though the best deals are often from local societies.”