Tesco is to leave shopping trolleys at its biggest stores unlocked when the new £1 coin launches.
The supermarket giant said work was being carried out to change the locks on its trolleys, which will not currently accept the new 12-sided coins.
Other supermarkets including Asda, Morrisons and Sainsbury's have said their trolleys accept both the old coins and the new ones, which launch on Tuesday.
Of the 3,500 UK Tesco branches, fewer than 200 have trolleys which require a coin or keyring token to use them.
A Tesco spokesman told the BBC: "We're replacing the locks on our trolleys to accept old and new pound coins as well as existing trolley tokens."
The spokesman told the BBC that staff would ensure trolleys were returned to their parks.
The old round pound coin is set to be phased out completely by October 15.