Supermarket giant Tesco has confirmed it will continue accepting old round pound coins after they cease to become legal tender.
Shops to 'ignore' Royal Mint deadline on old pound coins
The firm will allow customers to pay with the old-style coins for a week after the October 15 deadline imposed by the Royal Mint.
It follows a similar announcement by discount retailer Poundland, which will be accepting round pounds until October 31.
A Tesco spokesperson said: "We've been updating our systems ready for the new pound coins, but to help customers who still have the old coins, we'll continue to accept round pounds at our tills and self-service machines for an additional week."
From midnight on Sunday October 15, the round pound will lose its legal tender status, meaning stores cannot hand out old pound coins as change and can refuse to accept them as payment.
People have been urged to rummage through their wallets, coat pockets, piggy banks and sofas so that they can spend them, bank them or give them to charity before this date.
But as well as Tesco and Poundland, a trade association representing small shops has advised its members to continue accepting the round coins to provide a "useful community service" to customers.
A spokesman for the Federation of Small Businesses told the Telegraph: "Shopkeepers will be aware that the Royal Mint has this deadline but at the same time they will not want to let their loyal customers down by saying they cannot pay with a round pound if they do not have any other change.
"It would help if small firms knew they were allowed a short transition period to collect the old coins if they wish to and are willing to bank them, but not give out to customers.
"This would provide a useful community service, allowing customers a few weeks to get rid of the final few pound coins in circulation."
Around 500 million old round pounds are believed to still be in circulation.
The new 12-sided pound coin, which resembles the old threepenny bit, entered circulation in March and boasts new high-tech security features to thwart counterfeiters.
The production of the new coins followed concerns about round pounds being vulnerable to sophisticated counterfeiters. Around one in every 30 old-style pound coins in people's change in recent years has been fake.
Major banks have said that while they encourage customers to allow enough time to hand in their old coins, they will continue to accept deposits of round pounds from their customers after October 15.
And people can also deposit the old coins into any of their usual high street bank accounts through the Post Office - even after October 15 - "until further notice".
The Post Office is also taking part in Pudsey's round pound countdown - collecting old round £1 coins for BBC Children in Need.
Chief executive and deputy master of the Royal Mint Adam Lawrence said: "The round pound has been in circulation for over 30 years but, as the deadline approaches, we are keen to encourage everyone to track down their final coins and use them.
"As the deadline is triggered, we are proud that the security features on the 12-sided £1 coin will help to safeguard our currency for years to come."