The architect - who has become a fan favourite - said he happened to be ill on the deadline day to apply so put himself forward.
Tom, 29, said: “My partner David had been trying to convince me for years to apply but I really didn’t want to be on TV.
“I was off ill from work and was watching re-runs of Bake Off and thought, ‘I wonder if applications are still open?
“When I checked, it was the last day they were open and I thought, ‘That must be a sign. What have I got to lose?’ It was serendipitous.”
Tom lives with dentist David in the Capital and he has quickly become a Bake Off fans’ favourite.
Being on the show is a massive boost for Tom, who tragically lost his twin brother in an explosion in Afghanistan where he was serving with the Army in 2013.
Twin Robert died when his armoured vehicle was struck by an improvised explosive device (IED) less than six weeks into his deployment in Helmand Province four years ago.
Tom now says he hopes to become the first Scot to be crowned Bake Off champ.
He added: “I’m fully aware how lucky I was to have been picked as a contestant.”