A financial expert is warning the €29m EuroMillions winner to be prepared for an onslaught of people looking for a cut.
There is still no clue as to the identity of the punter, or in which part of the country Friday's winning ticket was sold.
However, Pierce Grace, of Kevin Condon Financial Brokers, told the Herald that, once the winner was named, thousands of people would ask for a share.
"They will have requests coming out of their ears, because everyone is going to want a piece of that €29m," he said.
"Banks and financial institutions will be contacting them, offering tonnes of advice as to how to invest it.
"They will also get charities and thousands of people telling them why they need an X amount of their winnings.
"Most people will have genuine and very sad stories to share, and I'm not saying you shouldn't be charitable, but the winner needs to be smart."
Mr Grace added that, once the lucky punter claims their winnings, to immediately book a plane ticket and leave the country. "They should go on a holiday for about a month and let their winnings sink in before making any rash decisions," he said.
"On their return, they will need to seek some very good tax and accounting advice and avoid anyone pressuring them to make any quick decisions."
"With €29m in your pocket, there is no rush into making any financial decisions.
The National Lottery has made a fresh appeal to all its players to check their tickets to see if they are the lucky Irish winner of Friday's jackpot.
Excitement has reached fever pitch all over the country as speculation mounts as to who the winner is.
This is the 11th EuroMillions jackpot win here since it started in 2004, and brings Ireland's winnings past the €1bn mark.
It has not yet been revealed in what part of the country the winning ticket was sold.
The winning numbers are 11, 20, 35, 37, 45 and the bonus numbers are 3 and 6. The jackpot was €28,975,630.
National Lottery chief executive Dermot Griffin said it was important that people check tickets to see if they have won.
"This is an incredible amount of money to win," he said.
"We have no idea if it is one player or a syndicate, but we are delighted to have another Irish winner of EuroMillions.
"We urge all of our players to check their tickets to see if their numbers have come up.
"If somebody has discovered they are the winner, we advise them to stay calm. Winning this amount can be a huge shock," he added.
"Make sure you get good legal and financial advice, and contact the National Lottery as soon as possible, and we will guide you through the claims process and give any support you need."