Gerry Cannings, 63, and his wife Lisa, 48, from near Peterborough in Cambridgeshire, matched their numbers in the February 13 draw.
They were visiting friends in Slough and Mr Cannings spotted the National Lottery poster announcing the jackpot while buying a fish and chip supper.
Mrs Cannings, a school teacher, explained why the couple took a week to claim their millions.
She said: “I know it sounds mad but we had a guy in to paint the whole house. We”d been planning it for ages and had packed everything into boxes.
“We just thought it would be easier to wait, although it did mean that Gerry had to carry round the winning ticket in his wallet all week. It was very nerve-wracking.”
Mr Cannings, a retired teacher, said he had always dreamt of how he would spend his winnings.
The couple, who have three children and five grandchildren between them, bought the ticket for the draw on February 13 while visiting Gerry”s parents Victor and Joan Cannings at their home in Datchet, Berks.
Gerry had nipped out to buy fish and chips for his family from the Drunken Fish Shop when he spotted a National Lottery poster announcing the big rollover Lotto jackpot.
Feeling lucky, the keen golfer splashed out on five lines, and was amazed to find the next morning that they”d won the jackpot with the numbers 15, 16, 23, 39, 48 and 59.
Gerry said: “Dad does Lotto as well, plays the same numbers all the time and had a ticket that night too.
“So at about 10pm, Dad suggested we check the winning numbers. But we couldn”t find them on teletext so went to bed.
“Sunday morning came and I decided to check the internet. I started looking down the lines I had and then saw that the first line was the same as the one on the screen.
“Next I saw there was only one winner and then it hit me “Bloody hell we”ve got the whole lot!”
— The National Lottery (@TNLUK)
February 23, 2016
But he claimed his family didn”t immediately believe his luck – only realising he was right when their 11-year-old son read out the numbers from the TV.
“I double checked it, reading it forwards and backwards,” said Gerry.
“It just didn”t seem real but it looked right. I went and found Dad but it was obvious he didn”t believe me.
“I then went back upstairs to tell Lisa and said “What would you say if we won the jackpot?” She can tell if I”m lying by looking into my eyes so she knew immediately I was being serious.
“It was only when our 11-year-old son read out the winning numbers on TV and they matched did Dad finally believe me.
“Our son asked what it meant, I just said “Daddy”s won an awful lot of money!”.”
The couple, who have been together for 13 years, immediately called Camelot to have the win confirmed.
Gerry said he has always dreamt how he would spend a lottery win, not actually believing that it would come true, but he and Lisa now hope to help their children and grandchildren financially.
The couple are on the lookout for a larger home big enough to sleep all the family at Christmas.
Gerry, a keen golfer, is also after a car wide enough to take his golf clubs and the couple, who are huge Lord of The Rings fans, plan to visit New Zealand to see where it was filmed.
Gerry added: “We can go where we want – and travel First Class too.
“After looking after the family, what this money brings is a chance to enjoy new experiences and see places we thought we wouldn”t get to see.”
The couple”s win places them second in the Lotto rich list, just behind last month”s biggest ever Lotto winners, David and Carol Martin, and one other anonymous ticket holder, who both scooped a £33,035,323 jackpot prize each in the draw on 9 January.
Gerry and Lisa are among the 88 ticket-holders who have scooped £1 million or more since October.
This includes jackpot winners and the guaranteed millionaires made by Lotto Millionaire Raffle in each and every draw.