Big Finish Productions has, since 1999, had the license from the BBC to make Doctor Who audio plays. Big Finish has turned this into a gold mine. They have created new stories for the five remaining classic Doctor Who actors (Tom Baker, Peter Davidson, Colin Baker, Sylvester McCoy, and Paul McGann) and for many of the remaining companions as well. New companions for the Doctor have been created, old characters have been given new spinoff series, and the Whoniverse has been explored and expanded unbound by visual effects. The BBC seems to be quite pleased by Big Finish. Not only were the Eight Doctor’s Big Finish companions named-checked in “The Night of the Doctor,” their license has been extended til 2020.
However, one area has been verboten. The BBC has made any reference to the new Doctor Who series off limits. So no Ninth, Tenth, Eleventh, or Twelve Doctors or any of the new companions, monsters, or events can be used in any Big Finish production.