Banks are trying to derail plans to force them to pay back billions of pounds to victims of mis-sold debt insurance in the High Court today.

The British Bankers' Association trade body is attempting to overturn tough rules laid down by the City watchdog that could mean justice for millions.

But unlike the bank charges saga, you can still make a claim while the legal wrangling goes on. If you've had a loan or credit card over the past six years, you could be owed 1,000s due to payment protection insurance (PPI) mis-selling (see the PPI Reclaiming guide).

Many people have asked questions about this, so here's a simple Q&A to keep you up to speed.

Q. What's happening?

The banks are revolting. They're taking the regulator, the Financial Services Authority (FSA), to court in a case which could see the future of billions of pounds worth of mis-sold insurance decided.

The key to all this is the FSA wants banks to review their past sales, and where they identify wide-scale mis-selling (according to FSA definitions), they must contact customers themselves, possibly paying out, rather than waiting for victims to put claims in first.

The banks argue the review isn't fair and is based on 'retrospective' rule making. They claim the FSA is unfairly applying rules it drew up after those sales to judge the way earlier policies were flogged.

The case is expected to last four days, though the losing side is likely to appeal which will prolong the wait.

Q. What is PPI?

It's supposed to cover your loan or credit card payments, usually for a year, if you cannot work due to involuntary unemployment or sickness.

Policies themselves aren't bad, but the versions sold by banks are mega expensive and have been systemically mis-sold for years.

Q. How do I know if I've been mis-sold?

Mis-selling can happen for a number of reasons. The key is the seller should ensure the policy is appropriate for you, but in many cases it didn't. Cover was pushed by highly incentivised salesmen and women as these are hugely profitable policies, often much more profitable than the loans themselves.

Examples of mis-selling could be telling you it's compulsory when it's not, adding it on without authority, giving the self-employed cover for people in employment, not asking about pre-existing conditions and more.

Q. What should I do if I've been mis-sold?

If you think you've been mis-sold you should write a letter to your bank telling it why and asking for the cost back.Many people get 1,000s back big money.

Q. What if the bank has told me my case is on hold?

Sadly, this is happening across the country. There isno official 'hold' on PPI reclaiming, but the banks (other than Santander) are saying they won't deal with claims until after the result of the court case.

However, unlike the sanctioned hold that used to be placed on bank charges reclaiming, this isn't an official hold and the failure to deal with cases goes against the FSA and the Financial Ombudsman Service rules.

The important thing to remember is even if a bank puts you on hold, you still have a right to go to the Ombudsman, the independent adjudicator of financial disputes, though you must complain to the bank first.

Yet, with all this going on, the Ombudsman has become log-jammed, and it's taking over a year in some cases to get a result.

Still, the huge potential payouts mean it can be worth the wait, and as the Ombudsman is free and you don't need a claims handler to help, you'll get to keep all the cash from any settlement.

Further reading/Key links

Ombudsman guide: Financial Fight Back
Reclaim mis-sold debt insurance: PPI Reclaiming
Other issue-specific reclaim guides: Bank Charges, Credit Card Charges, Direct Debits, Setting Off, Mortgage Arrears, Endowment Mis-selling