If you haven't done it, and you think you *might* have been involved, you must submit your claim by midnight UK time or lose your claim forever.
It's not difficult. I just followed the links on my banks website and said I had no supporting documentation.
The onus is on them to find out.
Lloyds put a nice seven grand in my account and that was that.
Minimal effort required, and they have to respond to you within two weeks or something.
They send a letter for each claim, a form to fill in, but if you don't know anything, just say so, and post it back.
There is even a Which? thingy here if that helps.
https://www.which.co.uk/consumer-rig...m-mis-sold-ppi
I suspect if they don't have detailed records and they even *think* you might have a claim, they'll give you seven grand to close the case.
The penalties on them for failing to perform due diligence are quite significant I believe.