With the battle for this year's cash ISA pots heating up following the recent launch of Santander's 3.5 per cent Flexi ISA, and Barclays launching the Golden ISA paying 3.1 per cent just yesterday, analysis from experts at moneysupermarket.com has today clearly spelt out why using your ISA allowance is a no-brainer, particularly in an environment where rates are at an all-time low and inflation remains a threat to savers' real returns.

Basic-rate taxpayers who have saved the full allowance in the average cash ISA every year since ISAs were first introduced in 1999 will be £2,900 better off than a saver who has not used their allowance and saved in a like for like basic easy access account instead. The difference is even more marked for higher-rate taxpayers - those who have saved diligently within an ISA wrapper will have earned interest of £12,622 compared to someone who has saved in a basic easy access account who will have just over half of that amount, £7,030. Anyone invested fully into the top paying ISAs would have a total pot of over £46,000 as a result.

Kevin Mountford, head of banking at moneysupermarket.com said: "UK taxpayers who have managed to save in a cash ISA year after year since launch should be feeling pretty smug, and who can blame them! The tax free interest, particularly for higher tax rate payers is worth smiling about.

"Consumers that can afford to save should be looking at ISAs, without doubt. Although rates are currently low, we have started to see some attractive offerings from the likes of Santander and Nationwide, and the benefits of these tax-efficient wrappers should not be overlooked. Savers should also make sure they remain vigilant, and check the rates of their existing ISA's. Many older ISA accounts will have dropped rates significantly so transferring funds is essential; in most cases funds are transferable to their new ISA without losing the tax free status, although you do need to adhere to the ISA transfer rules. .

"The cash ISA allowance for under 50s is increasing to £5,100 from 6 April giving a greater incentive for tax paying savers. Over 50s have benefited from this limit since 6 October."

A recent poll of over 1,200 moneysupermarket.com users has revealed apathy towards ISAs with almost four out of ten respondents (37 per cent) planning not to use their ISA allowance for 2009/2010. A further 26 per cent said they couldn't be bothered to save at all, which is particularly worrying.