Customers are paying more for loans and having to stump up bigger deposits to buy homes, even though interest rates are at their lowest levels in history, according to research published yesterday.

Figures from financial information group Moneyfacts.co.uk showed that banks have been increasing rates on their products to bolster profit margins at a time when their profits are being dented by rising losses from customers failing to make loan payments on time.

The data coincided with figures from Barclays which reported a “significant decline” in profits at its retail and commercial arm in the UK in the first three months of the year because of repayment problems. The bank, which otherwise reported a 15% rise in group profits to £1.37bn, said customers were having difficulty with unsecured loans and overdraft limits while business customers were also missing repayments.

The historically low level of interest rates of 0.5% is making it difficult for Barclays to make money on its savings accounts at the same time as customers are forcing it to take losses because of problems with repayments. The bank is also being hit by the need to top up its pension scheme.

The Moneyfacts research pointed to a “staggering jump” in rates charged on loans. It cited the cost of borrowing £5,000, which it said was now being charged at 12.4% interest compared with 8.6% a year ago.

“In May 2007 a customer would have paid £664 interest on a £5,000 loan over a three-year term; today that has jumped to £957,” said Michelle Slade, analyst at Moneyfacts. “Rising unemployment has meant the risk of customers defaulting on unsecured loans has increased and this is being seen in higher rates.”

Barclays credit card arm, Barclaycard, made more profit in the first three months of 2009 than it did a year ago although it is also seeing higher impairment charges. Barclays finance director Chris Lucas said the business was continuing to turn away 50% of applicants and also taking measures to trim credit limits. Balances were flat, which industry experts suggested showed customers were holding back from large purchases on credit cards.

In the mortgage market, Barclays continued to increase its lending in an area that has experienced negative growth, with more customers repaying loans than taking out new ones. Barclays lent just over £1bn more in the first three months and was very selective about customers to whom it provided loans. The average loan-to-value was about 45%, meaning that customers would need to find a deposit of 55% of the value of their home.