TSB offers three kinds of special savings account - 30, 60 and 90 days. If you lodge between £1,000 and £4,999 in the 30-day account the interest rate is 4.25 per cent, whereas the same amount of money in a 90-day account will earn interest of 5 per cent.

However, even if you lodge £50,000 in the 90-day account the interest rate increases by only 1 per cent. The DIRT, as this is a SSA, is 20 per cent.

It has two fixed term deposit accounts, both requiring a minimum deposit of £5,000. One is a SSA and offers a rate of 5.5 per cent for six months. The same account held for a year gives 0.5 per cent less interest, whereas if you leave your money on deposit for two years an interest rate of 10.25 per cent is guaranteed.