Jonathan Gershfield makes his feature directorial debut after working on TV series including Big Train and Dead Ringers.
Wayne Marc Godfrey is producing for new production outfit RMPC.
Steve Lewis and Tony Owen wrote the screenplay, about ordinary people with unique dilemmas in life and love.
3 and OUT will shoot for six weeks in London, Liverpool and the Lake District.
Richard Greatrex (Shakespeare in Love, Run, Fat Boy, Run) will serve as DoP while Four Weddings and a Funeral veteran Jon Gregory will serve as editor.
Gershfield said: 'We have had a fantastic response to the film. A great original screenplay has attracted the perfect cast and crew. I couldn't have hoped for more.'