The talented teen had been invited to try out for the show after becoming an instant hit on YouTube back in 2010.
Then aged 15, Sam became an online sensation after he was filmed duetting with Michael Buble at a gig.
Producers from Britain's Got Talent quickly invited him to audition, but their strict contract had Sam rejecting their offer.
“They sent through a very detailed contract which you have to sign before auditioning," Sam's told revealed at the time. "I admit I’m cynical but we felt the contract was very restrictive. You have to remember Sam is just 15, he’s a child and still at school.
“He loves what he’s doing now, he does a weekly acoustic night, yet he wouldn’t be able to do any of that if he went on the show.
“He went from a boy to a man when he made the decision. When we were supposed to be at the audition last Saturday he was feeling a bit low, but he’s very young and a lot can happen.”
Instead, Sam will be seen singing to join either Team Wil.i.am, Jessie J, Danny O'Donoghue or Sir Tom Jones on The Voice this weekend.
The Voice UK airs Saturday night on BBC One from 7PM.
Browse pictures of the second week of blind auditions from The Voice 2013 below...