The owner of a lottery ticket bought in the Black Country has yet to come forward to claim prize money of £1.4m.
Organisers say time is running out for the winner who has until 1730 BST on Thursday to claim the money.
The ticket was bought on 6 November 2004 in Sandwell and the numbers drawn were 5, 17, 23, 26, 42 and 48.
Camelot is urging people to look at old shopping receipts, check pockets and other areas for what could be the winning ticket.
The numbers were from a special draw to mark the tenth anniversary of the National Lottery.
Three other people who shared the £10m jackpot have claimed their prize.