bank & mortgage statements, isa statements, credit card statements...

[moveon]

You get the idea... I am having a clear out.

What do I need to keep and for how long?

I don't run a business and I am PAYE. I have a mortgage already. I've just switched all my bank statements to online only.

Thanks

3 months, max

For ever and ever and ever.

blog.moneysavingexpert.com/2013/08/12/dont-throw-bank-statements-away-after-six-years/

And if they are all online, make sure you can actually access them for a long time, not just one year or whatever.

Credit card statements that show big purchases as long as you have the items as you may need proof of purchase in the event you are burgled - been there done that.
Bank Statements - for ever.
ISA at least this plus 6 further years just because you are PAYE doesn't mean HMRC can't investigate you. So payslips, P60s and P11Ds would be the same.

You should keep absolutely everything vaguely to do with tax for six years in case at some point you DO need to fill in a tax return (as I do this year because we sold our enforced second home and it's subject to CGT, though thank god we made a loss).

As for the rest, credit card statements for big purchases in case of theft is a good idea. But if you've never had PPI or a loan or one of the other financial products that may have been sold, there isn't really a need to keep bank statements longer than 6 years.