From midnight on Sunday 15th October, shops and businesses will not be accepting round £1 coins from customers and should not give them out as change. These coins will not be legal tender from Monday, 16th October. They are being replaced by the new 12-sided £1 coin which came into circulation in March this year.
If you find that you still have any round £1 coins after 15th October, they are not worthless and can still be deposited into bank accounts at most high street banks and the Post Office.