There is just under one month left to spend your old round £1 coins.

The new 12-sided coins have been in circulation since the end of March and will take over from the old coins from October 16.

The Treasury and Royal Mint estimate that about 500 million round pounds are still out there.

After October 16, any unspent old £1 coins can be traded in at banks but this is only a temporary option.

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The Royal Mint said: “We would encourage you to spend, bank or donate your round £1 coins before October 15.

“We have urged businesses and their frontline staff to, where possible, prioritise the new coin when giving customers their change.

“Customers are entitled to ask for their change in any way they wish, but until October 15, businesses can continue to give out the old coin.”

The new £1 coin

The new coin came into circulation on March 28, replacing the round £1 coin which has been in circulation since 1983.

The new coin has been called “the most secure in the world” as they have high-tech features to make it harder to copy them.

There are more than 1.5 billion of them in circulation. 

About one in 30 of the old round £1 coins in circulation is a counterfeit. 

Can you still be given an old £1 coin as change?

Up until October 15, you can still be given the old coins as they still count as legal currency.

However, you have the right to ask for a new £1 coin instead. Businesses don't have to comply.

A spokesperson for The Royal Mint said: “We have urged businesses and their frontline staff to, where possible, prioritise the new coin when giving customers their change.

"Customers are entitled to ask for their change in any way they wish, but until October 15, businesses can continue to give out the old coin.”

What about after October 16?

After 11.59pm on October 15, businesses are under no obligation to accept the round £1 coin.

A spokesman for The Royal Mint said: "Following the ending of legal tender status, the current round £1 coin can continue to be deposited into a customer’s account, either business or personal, at most high street banks, provided that you hold an account with them.

"Specific arrangements may vary from bank to bank, including deposit limits. It is recommended that you consult with your bank directly."