The National Lottery is urging players to check their tickets as two jackpot winners, set to be multi-millionaires, are yet to come forward.
One unclaimed ticket, purchased in store on Saturday, holds £10.6 million, while the other, bought on Wednesday, is worth £2 million.
The players have just under six months to claim their winnings before the money is donated to causes across the UK.
Andy Carter, senior winners’ advisor at Allwyn, National Lottery’s operator, said, “We urge Lotto players to check their tickets in case they are one of our would-be multi-millionaires.
“Check your bags, coat pockets – down the back of the sofa even - as the lucky tickets are out there! Landing either of these jackpots will change lives and I look forward to meeting our lucky winners and paying out their incredible prizes in the run up to Christmas!”

On 4 October, one ticket matched the numbers 06, 08, 12, 33, 49, 59, securing the winning jackpot of £10,633,323. A second ticket purchased on 8 October hit the £2m jackpot, matching numbers 02, 21, 42, 48, 56, 57.
The ticket holders have 180 days from the day of the draw to claim their winnings. If unclaimed, the money will be donated to Good Causes, which funds projects across the country, supporting arts and sports sectors, local communities and preserving national landmarks.
Simon Horne from the National Lottery said: “While we would much prefer a player who's played to come forward and claim the prize, if they don't, then that money is still going to help a lot of people through going to the Good Causes.” Occasionally, prizes do go unclaimed, Mr Horne said.
“Fortunately, players are very good at checking their tickets, checking their emails, and coming forward very quickly to claim their prizes.”

The National Lottery is urging anyone who believes they have a winning ticket to go in store or use their app to check their retail tickets or check their email to see if they have won from an online ticket.
They ask that any players who believe they have won call the National Lottery Line on 0333 234 5050 or email help@national-lottery.co.uk. “We are keen to pay you your big prize,” Mr Horne said.
He said winning this much money can be life-changing. “We've seen, over the years, we've made over 7,400 millionaires, and the effect that it can have on the individual, their family, their friends, and also good causes in the community around them, the charities they want to support can be huge.
“It's exciting for a player, and we look forward to meeting these players and supporting them as they start their life changing journey.”
Since it launched in 1994, the National Lottery has paid out more than £95B in prizes.
Lucky Lotto player scoops life-changing £10.6m jackpot
Single EuroMillions ticket holder wins £26 million jackpot
Single UK ticket-holder wins £26m EuroMillions jackpot
Premium Bonds prize checker: When is October’s draw and how do I check if I’ve I won?
Travellers told to brace for delays as new EU entry-exit system begins on Sunday
‘Ball junkie’ dogs can be addicted to their toys, scientists suggest