It's the question we've been waiting years to know the answer to: whether excessive overdraft fees of up to £35 a time for slipping overlimit can be deemed fair by law.
If the Supreme Court rules they do, it could re-open the floodgates for millions to reclaim their cash.
This will be a fast-moving story so please return to www.moneysavingexpert.com/bankchargesresult from 9.45am on Wednesday (25 November), and throughout the day, for full details and what it means for you.
What's the background?
After the banks paid out over a billion pounds to reclaimers, in July 2007 the Office of Fair Trading (OFT) agreed to a test case with the banks to sort the law out, at which point most claims were put on hold.
First, the courts have to decide if fairness rules apply (which is what today's judgment is all about). If they apply, the OFT then has to decide if charges are indeed unjust.
The High Court has ruled fairness laws apply, the banks tried to overturn this decision at the Court of Appeal and failed. Now the Supreme Court has to give its verdict following another appeal by the banks.
What if the banks lose?
The next step is for the OFT to decide if charges are fair. But as it's the group that has taken the banks to court, it's likely to suggest they are unjust.
But then it's expected that the banks will challenge any OFT ruling that goes against them, to further delay matters. However, politicians have already stated they are against that, and would push for a negotiated settlement.
If charges are deemed unfair, the one million-plus people with claims on hold and up to 8 million more eligible to claim could be due vast compensation: £100s, even £1,000s each.
However, details regarding exactly who that applies to and how much they would be able to claim is still a long way off.
What if the banks win?
This would represent a massive blow to reclaimers, but this site will continue to pursue avenues to get consumers their cash back.
Further reading/Key links