A winning lottery ticket worth £173,557 is yet to be claimed in the Carmarthenshire area.
Lottery bosses are urging players to check their tickets this week as the win could set hearts a-flutter this Valentine's Day.
The lucky winner matched five numbers and the bonus ball in the Lotto draw on 1 December 2012.
If the ticket holder doesn't claim the prize by 30 May this year then the prize money, plus all the interest it has generated, will go to good causes - adding to the £29 billion already raised through sales of lottery tickets since The National Lottery launched in November 1994.
A National Lottery spokesperson said: "We're desperate to find this missing ticket-holder and unite them with their winnings – this really could be the best way to celebrate Valentine's Day and show your partner how special they really are.
"We have the champagne on ice and a dozen red roses at hand, as well as our fingers crossed, that the lucky winner comes forward to claim their win."
With all National Lottery draws, players have 180 days from the day of the draw to claim their win if they have the winning ticket. Anyone who believes they have the winning ticket for any of the National Lottery draws within the 180-day deadline should call the National Lottery Line on 0845 910 0000.
