Consumers hoping to reclaim bank charges will find out this morning if they can take their battle any further through the courts.

The Court of Appeal is set to give its verdict on a 2008 ruling, which backed the right of the Office of Fair Trading (OFT) to decide whether banks’ terms and conditions are fair.

If the Court upholds the original ruling, the OFT could decide what would be a fair charge for going into unauthorised overdraft, and could force lenders to repay millions of pounds in charges.

However, if the banks are unsuccessful in their appeal, they could take the case all the way to the House of Lords.

Which? personal finance campaigner Doug Taylor, said: “We hope the Court of Appeal is unequivocal in agreeing with the original High Court decision.”

The case was first brought to the courts in 2007, with a ruling handed down in April 2008.

The High Court agreed that none of the historic charges could be seen as ‘unfair penalties’ – except for some of NatWest’s – but did agree the OFT has the right to decide whether the charges are unfair.

In the meantime, anyone who has had an unauthorised overdraft charge levied against them since July 2001 should write to their bank and ask for their money back, Which? advises.

The Financial Services Authority (FSA) has frozen claims until the test case has finished. Under the terms of this waiver, their bank must acknowledge their complaint within five working days.