Customers spending time in researching individual savings account (Isa) rates are probably wasting their time, according to a financial expert.

Phil Perry, director of Ark Financial Planning, said that moving from one bank to another for a difference of 0.1 or 0.2 per cent would cost clients more effort and time than any significant savings in their Isa accounts.

He added that fixed rates were arguably the best options available to savers in the present market scenario. However, Mr Perry cautioned against investing in Isa accounts that were fixed for more than two years, because interest rates were expected to climb in the future.

He explained: "I would not want to be tied into a fixed rate for longer than two years, because I would think I might start to fall behind."

His comments following in the wake of a Guardian article that exposed the piteous rates offered on Isa accounts.

An unhappy customer with the Royal Bank of Scotland earned a paltry £35.84 on £40,000 before transferring his saving to one with the Northern Rock, according to the newspaper.

Meanwhile, Nationwide Isa clients reported earning £4.97 on savings worth £2,556 and £19 for around £8,000.

The rise in the number of complaints has lead Consumer Focus to ask the Office of Fair trading to evaluate the Isas available to customers. It has been estimated that savers investing in Isa accounts could be collectively missing out on £3 billion worth of interest each year.

Most Isa saving rates that average around three per cent peter out after the first year, with most customers left stuck with a 0.5 per cent rate, the organisation indicated.

The investigation concluded that customer could skirt around the low rates by changing who they bank with. However, the investigation also showed that lengthy bank procedures often hindered clients from transferring their accounts from one brand to another.