You have until 15th October to find £420m

Pound coins in hand
Time to get your metal detector out...
"After 15 October they can only be exchanged at banks or Post Offices," Georgie Frost, GoCompare
  • | by Alice Morgan

In just a couple of weeks, the soon to be old-school round pound coin will no longer be legal tender.

In case you missed it, the UK is making room for the new kid on the block - the 12 sided coin - which means you'll need to have used up all your old round ones by the 15 October.

So Britain, get ready to scour your wallets and empty your savings tins!

Because according to new research by GoCompare Money, there's £420m worth of old £1 coins just lying around, waiting to be spent.[2]

Where have all the old coins gone?

Pound coins in a row

"Already over a billion of the 1.7 billion have been returned since the new 12-sided bimetallic £1 coin was introduced back in March over forgery concerns, with the Royal Mint estimating one in 30 round pounds was a fake," explains Georgie Frost, head of consumer affairs at GoCompare.

But there are still plenty more to be found.

If you're wondering where to start when it comes to digging out your fortune in pound coins, we might just have the answer.

Most of them are actually in coin jars where 36% of UK adults say they store them.[2]

And it's worth checking your car too as 32% of us Brits keep coins there for supermarket trolleys and parking.

Get the kids involved as well - 13% of the population say their old pound coins are kept in their children's piggy banks.

Be sure to look in old coat pockets and down the back of your sofa too - there's always some change lurking there.

What can you do with the old ones?

Well, the obvious answer here is to spend them.

Rather than lugging a heavy bag of coins around, take them all to your nearest Coinstar machine where you can exchange them for a voucher to be spent in store. And if you don't want to shop in store, you can exchange the voucher for cash at a customer service desk. Winner!

If you'd rather save your money, cash your pound coins in at your bank but make sure they're bagged up first - you might meet a very unhappy cashier at the till if you don't.

Alternatively, if you're feeling particularly generous, you could always donate your round pounds to a worthy charity. There are some who are accepting old pound coins such as the Rainbow Trust and Epilepsy Action or you could cash them in and donate via a charity website.

Be quick if you don't want to cash them in though as Frost explains, "After 15 October they can only be exchanged at banks or Post Offices."

Rare £1 coins

Pound coins in a row

Keep an eye out for some interesting designs while you're sorting through your old pound coins - you might just have a bobby dazzler on your hands.

A new but misshapen £1 coin is currently going for £2,000 on eBay and there's a new trial one up for £1,500.[3]

Coins with bridges on them such as the Menai Bridge and Forth Railway Bridge are also very rare and might fetch a handsome sum online.

Other rare pound coins include the 2011 Cardiff City and Edinburgh City coins which may just get you more than their face value.

So don't be too hasty - it's worth checking your old coins before you spend them or cash them in.