Accountants are finding ever-more inventive ways for City high-flyers to avoid next year’s 50% tax on their bonuses, but ordinary taxpayers can also save thousands by making use of legitimate tax breaks.

Consumers will waste more than £10 billion in unnecessary tax in 2009, said unbiased.co.uk, the advice website — an increase of £700m on 2008.

Here are some more ways to limit your tax.

1. DON’T SNIFF AT ISA BREAKS

Savers are always told to make the most of the tax breaks available on Isas, although the savings on one year’s allowance are small. For example, investing £3,600 in the average cash Isa at 0.41% will produce a tax saving of just £5.76 a year. Even with the higher cash allowance of £5,100 for over-fifties, available from October, the saving would be just £8.16.

The savings can be greater, however, if you have been saving into an Isa for a while and you transfer the entire amount into one of the better-paying Isas on the market. For example, those who saved the maximum into a cash Isa every year since the scheme launched 11 years ago would have a tax-free pot including interest of about £46,000 by now, according to financial data firm Defaqto.

Put this into Newcastle’s 5% fixed-rate Isa, which allows savers to pull out their money with 90 days’ notice, and you would earn £2,300 interest in the first year, with a tax saving for higher-rate taxpayers of £1,380.

Not all Isas accept transfers. Of the top six deals, only three — Newcastle and Manchester building societies and Standard Life — do so. Our best-buy Isa tables tell you which of the top deals will accept cash transfers.

You can invest more in a stocks and shares Isa — £7,200 or £10,200 for the over-fifties from October — and the tax savings over 20 years are significant. If a higher-rate taxpayer invested £7,200 at the start of each year for 20 years, and their funds grew 5% a year, they would have a pot of £249,979 within the Isa compared with just £193,467 outside because of the impact of income tax and capital-gains tax (CGT), according to Grant Thornton, the accountant — a difference of £56,512.

If they drew an income of 5% in retirement they would earn £9,673 a year gross, or £5,804 after higher-rate tax, outside an Isa. Within an Isa, however, their gross income would be £12,499 — more than double the amount had they invested outside the tax-free shelter as they had a bigger pot to start with and the income is also tax free.

2. USE OTHER PERKS

Instant income-tax refunds worth hundreds of thousands of pounds are available if you invest in schemes which have been designed to support enterprise.