The number of customers trapped in poor-paying ISAs has doubled in the last two years . Savers are being hit with the worst interest rates in history with a third of Isa accounts now paying less than 1 per cent a year . The number of customers trapped in poor-paying Isas has doubled in the last two years as interest rates on them plummet to new lows . One in six accounts offer less than the Bank of England ’ s base rate at just 0.5 per cent , while some savers are stuck on rates of 0.1 per cent . The proportion of these tax-free accounts returning below 1 per cent has doubled in the last two years , from one in six to one in three . It means that on the current worst Isa rate of 0.1 per cent , someone depositing £15,000 would make a paltry £15 a year in interest . In contrast , a saver on the most competitive rate of 1.5 per cent would make £225 – a difference of £210 a year . With four weeks left to use this year ’ s £15,000 Isa allowance , many savers will question the value of such accounts . The Building Societies Association said there was not ‘ one single factor ’ driving down Isa rates but said the ‘ persistently low base rate ’ had contributed to lower returns . A spokesman added : ‘ I don ’ t think there is a hard correlation between Isa rates and mortgage rates . The Building Societies Association said there was not ‘ one single factor ’ driving down Isa rates but said the ‘ persistently low base rate ’ had contributed to lower returns . ‘ Each provider has to strike a balance between savings rates and mortgage rates as they need both savers and borrowers. ’ Experts also blame the Government ’ s Funding for Lending scheme , which allowed banks to borrow cheaply in return for handing out home and business loans after the economic crisis . The scheme meant that banks were no longer dependent on savers ’ money – reducing the need to offer competitive rates , it is claimed . Anna Bowes , of independent savings website Savings Champion , said : ‘ After six years of the base rate at 0.5 per cent , this is toughest time on record for savers , and Isa savers have certainly not been immune to the pain . ‘ Isas were once seen as the go-to savings product due to their tax-free status . ‘ But with rates at an all-time low , some savers – especially those looking to build up a short-term lump sum for perhaps a house deposit or a car – may need to be more creative . ‘ High-interest savings accounts offer rates of up to 5 per cent before tax , so even a taxpayer could find that this route could earn them more interest. ’ But Rachel Springall , of the website Moneyfacts , warned : ‘ Despite the gloomy outlook on savings rates , consumers need to use their tax-free allowance or lose it . ‘ While there might be an abundance of taxable savings accounts out there , it is always worthwhile to track down an Isa equivalent and use the yearly tax-free allowance. ’ Savers have lost out on £4.7billion in the last three years due to low interest rates .
Figures show savers are being hit with the worst interest rates in history . One of ISA accounts are now paying less than one per cent per year . A third in six accounts offer less than Bank of England 's 0.5 % base rate . Number of tax-free accounts returning less than 1 % has doubled .