Time is running out for you to spend old £1 coins as the deadline looms.

Ipswich Star: The new 12-sided �1 coin. Picture: ROYAL MINT/PA WIREThe new 12-sided �1 coin. Picture: ROYAL MINT/PA WIRE

The Treasury says there are now more of the new 12-sided £1 coins than the old round pound.

From Sunday, October 15, shops can refuse the old version of the coin so people are advised to spend them or change them before the cut-off point.

The new £1 coin was introduced on March 28 and has a hidden built-in security feature to prevent forgery and a holographic image that changes depending on what angle it is viewed at.

What do I do with old coins after they’ve been withdrawn?

You can still deposit them at most high street banks. They may also exchange them for the new £1 coins, but you’re best to check first.

Why was the coin changed?

The coin was changed because the old £1 coin is heavily counterfeited - the Royal Mint estimates around one in 30 of the coins in circulation today are fake.

The new version is a lot harder to counterfeit,

What are the new security measures?

As well as the grooved sides, the distinctive 12-sided shape and the two different metals used in its construction, the new coin incorporates a holographic-like image which changes based on the angle you view it from, very small lettering on the inside rim and a hidden, built in security feature to protect it from forging in the future.

The new £1 coin has been dubbed the most secure coin in the world.

Any other monetary facts I need to know?

The Bank of England has already changed the £5 and £10 notes from paper to polymer, but the £20 versions will not be around until 2020.

The £5 note, which features former Prime Minister Sir Winston Churchill, was released in September 2016.

The £10 note features English novelist Jane Austen as well as a quote from Pride and Prejudice when Miss Bingley said: “I declare after all there is no enjoyment but reading!”

It went into circulation on September 14 and the old notes will be phased out in spring 2018.

And for those of you hoarding £50 notes, do not panic – there are currently no plans to withdraw them.