There's only one week left before your paper £20 and £50 notes can't be spent anymore and essentially become worthless in shops.
The last day that these notes are considered legal tender is 30 September, so the clock is ticking for anyone who wants to spend their cash before it goes out of circulation.
New £20 and £50 notes have been in circulation for a while now, with the polymer £20 released on 20 February, 2020 and the new £50 with Alan Turing on them issued on 23 June, 2021.
The old notes with Adam Smith on the £20 and the £50 bearing the images of Matthew Boulton and James Watt are just days away from no longer being legal tender, so they will soon either end up as compost or collectors items.
Luckily for anyone sitting atop a mountain of paper notes, just because you can't spend them doesn't mean you'll lose out on their value.
You can still take your old notes to banks and have them swapped for nice new polymer bank notes which you can spend to your heart's content.
With the old £20 and £50 notes going out of circulation it represents a full transition to polymer bank notes in the UK.
Switching to polymer makes the notes more durable against wear and tear, as well as harder for criminals to counterfeit.
Counterfeit notes have no value and if they get spotted as a fake won't be accepted for payments, while banks won't exchange them for actual money even if you ended up with one through no fault of your own.
Despite the tougher challenges, criminals still make fake polymer notes which could leave you out of pocket.
The new polymer notes will end up being replaced themselves at some point, as current British money bears the image of Queen Elizabeth II.
Once images of King Charles III have been selected to go on newly minted and printed coins and notes, a new range of cash will be released into circulation, slowly replacing the money bearing the image of the Queen.
While it may take some time for this to happen, the rate at which money can be changed in circulation is staggering.
Only a few years ago every note in the UK was paper, these days you'd have a lot of trouble finding one and the last few paper notes out there are just a week away from being rendered obsolete.
As for what happens to the old notes, they get destroyed by being composted which means at some point in your life you've probably eaten something which was grown with help from old bank notes.