Saturday's Lotto draw will be a triple rollover - only the third one since the lottery was launched 13 years ago.
The jackpot will reach an estimated £18m on SaturdayWinning numbers in the Lotto main draw were 3, 10, 22, 25, 31 and 49.
No-one has won the jackpot, now put at £18m, since 20 October, although draws were held on 24, 27 and 31 October.
The bonus number was 4.
If no-one matches all six numbers drawn, the jackpot will be "rolled down" to the next prize level - five main numbers plus the bonus ball.
The estimated jackpot is £18m.
The first triple-rollover jackpot, worth £22.1m, was shared in May 2004 between six winners.
The Thunderball numbers were 1, 2, 3, 29 and 34. The Thunderball was 11.
Last year an £18.7 million triple rollover jackpot was split between a retired couple and a syndicate of workers from a postal sorting office in Manchester.
Winning numbers in Saturday's Lotto Dream Number game were 9, 7, 3, 6, 2, 6, 3.
Operator Camelot said it expected a rise in ticket sales ahead of Saturday's 2000 GMT draw.
Saturday's Lotto draw was a triple rollover - only the third one since the lottery was launched 13 years ago.
"Whatever happens, whenever there is a big Jackpot like this, the whole nation comes out as a winner - as more people playing means more money raised for the good causes," a spokesman said.
