The paper that only matters once
A warranty matters on one day in three years. Keeping everything is how you guarantee you cannot find it on that day.
There are two failure modes with documents and most people run both at once: a drawer holding six years of supermarket receipts, and no copy of the thing that is actually needed when something goes wrong.
The sorting rule that works is not about tidiness. It is about the one day the paper matters.
Three questions per piece of paper
Could I get another copy in an hour if I lost this? Bank statements, utility bills, most invoices — yes, from a website. Those do not need keeping; they need knowing where to download from.
Does it prove something about money or ownership? Contracts, the car's papers, the deed, the insurance policy, anything with a signature. Keep, and keep findable.
Does it have a date on which it stops mattering? A warranty, a guarantee, a visa, an MOT. Keep until that date, and put the date itself somewhere you will see it — the date is worth more than the paper.
Scan the second category, not all of it
Photographing everything produces a folder of eight hundred images named IMG_4432, which is the drawer again with worse lighting. Photograph the ones from the second and third questions, name them so a stranger would understand, and stop.
A good name has the year, the thing and the party: 2026-car-insurance-allianz. You will search by one of those three, and never by the date you took the picture.
The copy that is not in your house
Everything important should exist somewhere other than the building it describes. A fire, a flood or a burglary takes the documents about the fire, the flood and the burglary.
This does not have to be sophisticated. Copies in one place online, under your own account, with a password you have not reused. The failure here is almost never a hacker; it is never having made a copy at all.
Where a space helps
Documents kept here sit next to the dates they depend on, so the warranty that expires in March shows up in March rather than in the drawer. Files live outside the release, they are deleted with the space, and they are not shared with anybody.