The deadline for spending the current issue pound coins has been announced.
A new design of pound coin, announced late last year, will launch in March, with the old version becoming obsolete just over six months later.
Once the deadline has passed the old pound coins won’t be worth their weight in gold - or more precisely copper, zinc and nickel.
The Government said it is launching a campaign to help raise awareness and encourage the public to return the old one pound coins - identified by their ‘round’ traditional design.
This is the first time the one pound coin has been introduced in over thirty years.
Around £1.3 billion worth of coins are stored in savings jars across the country, and the current one pound coin accounts for almost a third of these.
As a result of the change, the estimated £433,333,333 pound coins in jars will expire on midnight 15 October 2017.
Many millions more will be lost to coins lying about in pockets and down the back of sofas.
The new 12-sided pound coin will be the most secure in the world and will enter circulation on 28 March.
It boasts several new security features, including a hologram, to prevent counterfeits, which cost taxpayers and businesses millions every year.
Chief Secretary to the Treasury David Gauke said: “March 28 should be an important date in everybody’s calendar this year - as we will have a new quid on the block.
“This is a historic moment as it’s the first time we’ve introduced a new £1 coin since 1983, and this one will be harder to counterfeit than ever before.
“Our message is clear: if you have a round one pound coin sitting at home or in your wallet, you need to spend it or return it to your bank before 15 October.”
Reaction to the announcement of the new 12-sided coin last year showed just how much people really hate change.