Confirming the news to Sky Sports, Town Chief Executive Derek Bowden said: "Kelvin Davis is currently in Sunderland, I believe. We've accepted an offer from Sunderland for Kelvin. He's probably with Mick McCarthy now.
"If he can agree personal terms and likes what he sees up there, then I guess he will move on but it's very much in his court. We believe it's a fair offer for the player, particularly as he came in on a free transfer."
Should the transfer go ahead Town boss Joe Royle will be looking for a new goalkeeper to replace the former Luton Town stopper rather than giving the job to current second choice keeper Lewis Price.
Davis could be the second player to leave Town in 24 hours with Darren Bent having already signed for Sunderland earlier today in a £2.5M deal which could increase to £3M depending on future peformance.