Current account holders were hit with £4.7bn worth of overdraft charges in the past year, Which? magazine said today.

Penalties of £20 to £30 are the norm for customers who exceed their authorised limits and go into the red, the consumer group found.

Current account holders are typically charged an additional £25 to £30 for standing orders or direct debits paid out while over their overdraft limits.

Which? researchers found that HBoS, RBS and Natwest imposed the highest charges for current account holders going £50 over their £250 overdraft limit for three days.

They each imposed a £118 penalty, including charges for a cheque, direct debit and standing order which was paid out while the customer was over their limit.

Abbey had the second highest charges for the same scenario, at £110, compared to Nationwide at £101.50. Northern Rock, based in Newcastle, had the lowest charges at £28.

HSBC and Smile had overdraft "buffers" which meant charges did not apply to their current account holders in that scenario, Which? said.

Credit card companies also typically charge £20 to £25 if customers go over their credit limit or pay their bills late. The Which? report says the penalties are excessive.

The consumer group has written to the Financial Services Authority asking it to take prompt action to force banks to reduce their overdraft charges.