The Stolen Earth (2008)
You don’t get more ex-directory than the Tardis, so fans were thrilled when its phone number flashed on screen in this David Tennant episode. More than 2,500 people supposedly tried to call the number – 07700 900 461– expecting to be put through to the Time Lord. Unfortunately for them, it was chosen from a list of ‘safe’ disconnected numbers, meaning all they got was a dial tone or automated message.
Incidentally, the question of who might know the Doctor’s phone number has been central to this series’ overarching storyline. Either the Doctor has forgotten he gave it out to 7 billion people, or he’s dropped his phone in the toilet since then.