The presenter is set to swap hosting duties to take on the banker for the very first time in a bid to bag £500,000 for charity.
And Noel was just as much in the dark about competing on the show, which has already been recorded, as the ‘Deal Or No Deal’ audience.
Shortly after kicking off the special episode, comedian Sarah Millican appeared from the wings and announced she would be taking over hosting duties.
Noel then found himself competing to win £500,000 for his chosen charity, Children’s Hospice South West.
Speaking about the special episode, Noel said: “To be given the chance to play the game I am so very proud to host was a great honour and one of the biggest shocks of my professional life.
“I hate the Banker even more now! Playing for Children’s Hospice South West - a charity very close to my heart - was the icing on our 10th birthday cake."
The mysterious Banker added: “Noel was speechless when he realised he’d been pranked by the one true talent of the show, yours truly.
“Where have the years gone? I look withered, Noel looks years younger. That tells you a lot about who does all the hard work around here. I would say it’s been a pleasure, but it hasn’t.”
You can find out how he does when Channel 4 airs the charity special on 18 September.