- Completely Different Title: The French title is "Cyber Noël" (Cyber Christmas).
- Doubling for London: Gloucester doubled for Victorian London.
- Edited for Syndication: 60-minute distillations of this episode conclude on the "Bravo, sir!" scene and leave out the heartwarming closure that implies Rosita has become Jackson Lake's Second Love and the Doctor agreeing to stay for dinner. This creates the unfortunate effect of the last scene with him featuring him gloomily looking down at the crowd below, weary after recent events and taking the praise with a grain of salt.
- Recycled Set: The set for the cyberfactory is actually the Torchwood Hub set cleverly disguised.
- What Could Have Been:
- An early script draft had the story following on from the unused Cybermen cliffhanger for "Journey's End". The two inside the TARDIS would vanish, and the Doctor would realise that they were falling through the Time Vortex, and follow them to Victorian England.
- Russell T Davies considered having the Doctor's companion be a grown-up version of the Little Match Girl.
- Davies considered setting the story in the court of King Henry VIII, but rejected this notion on the grounds that it would not feature enough recognizable Christmas traditions (since these typically postdated the sixteenth century). He also mulled another completely new idea, about a hotel which becomes displaced in time.
- Davies later realised that it would have been a better ending to have Miss Hartigan redeem herself by making the falling CyberKing disappear, rather than introducing what Davies calls "a silly Dalek continuum dimension vault" to the plot. Davies states that he "can't bear that there could have been a better ending than we actually transmitted".
- Martin Clunes was orignally cast as Jackson Lake but pulled out.
- Word of God: According to Neil Gaiman, the Cybus Industries Cybermen "zapped off into time and space" by the Doctor at the end of this episode eventually encountered the Mondas Cybermen; their "cross-breeding and interchange of technology" resulted in the variety of Cybermen seen in "Nightmare in Silver".
- Working Title: "Court of the Cyber King".
Trivia / Doctor Who S30 E14 "The Next Doctor"