Consumer support group, Which? estimates that a further 8 million Britons will reclaim unfair bank charges if the ruling expected on Wednesday this week goes in favour of the Office of Fair Trading.

Claiming bank charges has been suspended since July 2007, following a joint decision by the Office of Fair Trading and the banks to run a test case through the courts. One High Court date, an Appeals Court date, a three day House of Lords hearing and over two years later and the Supreme Court is now just two days away from making a decision with the potential to change personal banking entirely.

There are already a million applications for bank charge reclaims on hold pending a decision. Prior to the suspension, it is estimated that the banks had already reimbursed almost £1 billion to consumers who had claimed back the unfair bank charges.

But Which? now estimates that another 8 million consumers will follow suit if the Supreme Court upholds the ruling made by both the High Court and Appeals Court. If that happens, consumers will be able to claim back bank charges from the past 8 years. While this is undoubtedly good news for those who have been hit by the charges, it does raise questions about the future of free banking. There are concerns that banks may start charging a monthly fee for a personal bank account or even start charging for every single ATM transaction. This will be a huge blow for those who enjoy free banking without ever going into the red, however, last week Santander, the owners of Abbey introduced a completely fee free account for holders of their mortgages. Could this open the door for the other banks to follow?