From TARDIS Index File, the free Doctor Who reference.

Doctor Who production codes do not always follow air dates.

TV story production codes

• A: An Unearthly Child a.k.a. "100,000 BC", "The Tribe of Gum"
• B: The Daleks a.k.a. "The Dead Planet," "The Mutants"
• C: The Edge of Destruction a.k.a. "Beyond the Sun", "Inside the Spaceship"
• D: Marco Polo
• E: The Keys of Marinus
• F: The Aztecs
• G: The Sensorites
• H: The Reign of Terror a.k.a. "The French Revolution"
• J: Planet of Giants
• K: The Dalek Invasion of Earth
• L: The Rescue
• M: The Romans
• N: The Web Planet
• P: The Crusade
• Q: The Space Museum
• R: The Chase
• S: The Time Meddler
• T: Galaxy 4
• T/A: Mission to the Unknown, a.k.a. "Dalek Cutaway"
• U: The Myth Makers
• V: The Daleks' Master Plan, a.k.a. "The Dalek Master Plan"
• W: The Massacre of St Bartholomew's Eve, a.k.a. "The Massacre"
• X: The Ark
• Y: The Celestial Toymaker
• Z: The Gunfighters
• AA: The Savages
• BB: The War Machines
• CC: The Smugglers
• DD: The Tenth Planet
• EE: The Power of the Daleks
• FF: The Highlanders
• GG: The Underwater Menace
• HH: The Moonbase
• JJ: The Macra Terror
• KK: The Faceless Ones
• LL: The Evil of the Daleks
• MM: The Tomb of the Cybermen
• NN: The Abominable Snowmen
• OO: The Ice Warriors
• PP: The Enemy of the World
• QQ: The Web of Fear
• RR: Fury from the Deep
• SS: The Wheel in Space
• TT: The Dominators
• UU: The Mind Robber
• VV: The Invasion
• WW: The Krotons
• XX: The Seeds of Death
• YY: The Space Pirates
• ZZ: The War Games
• AAA: Spearhead from Space
• BBB: Doctor Who and the Silurians
• CCC: The Ambassadors of Death
• DDD: Inferno
• EEE: Terror of the Autons
• FFF: The Mind of Evil
• GGG: The Claws of Axos
• HHH: Colony in Space
• JJJ: The Dæmons
• KKK: Day of the Daleks
• LLL: The Sea Devils
• MMM: The Curse of Peladon
• NNN: The Mutants
• OOO: The Time Monster
• PPP: Carnival of Monsters
• QQQ: Frontier in Space
• RRR: The Three Doctors
• SSS: Planet of the Daleks
• TTT: The Green Death
• UUU: The Time Warrior
• WWW: Invasion of the Dinosaurs
• XXX: Death to the Daleks
• YYY: The Monster of Peladon
• ZZZ: Planet of the Spiders
• 4A: Robot
• 4B: The Sontaran Experiment
• 4C: The Ark in Space
• 4D: Revenge of the Cybermen
• 4E: Genesis of the Daleks
• 4F: Terror of the Zygons
• 4G: Pyramids of Mars
• 4H: Planet of Evil
• 4J: The Android Invasion
• 4K: The Brain of Morbius
• 4L: The Seeds of Doom
• 4M: The Masque of Mandragora
• 4N: The Hand of Fear
• 4P: The Deadly Assassin
• 4Q: The Face of Evil
• 4R: The Robots of Death
• 4S: The Talons of Weng-Chiang
• 4T: The Invisible Enemy
• 4V: Horror of Fang Rock
• 4W: The Sun Makers
• 4X: Image of the Fendahl
• 4Y: Underworld
• 4Z: The Invasion of Time
• 5A: The Ribos Operation
• 5B: The Pirate Planet
• 5C: The Stones of Blood
• 5D: The Androids of Tara
• 5E: The Power of Kroll
• 5F: The Armageddon Factor
• 5G: The Creature from the Pit
• 5H: City of Death
• 5J: Destiny of the Daleks
• 5K: Nightmare of Eden
• 5L: The Horns of Nimon
• 5M: Shada
• 5N: The Leisure Hive
• 5P: State of Decay
• 5Q: Meglos
• 5R: Full Circle
• 5S: Warriors' Gate
• 5T: The Keeper of Traken
• 5V: Logopolis
• 5W: Four to Doomsday
• 5X: The Visitation
• 5Y: Kinda
• 5Z: Castrovalva
• 6A: Black Orchid
• 6B: Earthshock
• 6C: Time-Flight
• 6D: Snakedance
• 6E: Arc of Infinity
• 6F: Mawdryn Undead
• 6G: Terminus
• 6H: Enlightenment
• 6J: The King's Demons
• 6K: The Five Doctors
• 6L: Warriors of the Deep
• 6M: The Awakening
• 6N: Frontios
• 6P: Resurrection of the Daleks
• 6Q: Planet of Fire
• 6R: The Caves of Androzani
• 6S: The Twin Dilemma
• 6T: Attack of the Cybermen
• 6V: Vengeance on Varos
• 6W: The Mark of the Rani
• 6X: The Two Doctors
• 6Y: Timelash
• 6Z: Revelation of the Daleks
• 7A: The Mysterious Planet
• 7B: Mindwarp
• 7C-1: Terror of the Vervoids
• 7C-2: The Ultimate Foe a.k.a. "Time, Inc."
• 7D: Time and the Rani
• 7E: Paradise Towers
• 7F: Delta and the Bannermen
• 7G: Dragonfire
• 7H: Remembrance of the Daleks
• 7J: The Greatest Show in the Galaxy
• 7K: Silver Nemesis
• 7L: The Happiness Patrol
• 7M: The Curse of Fenric
• 7N: Battlefield
• 7P: Survival
• 7Q: Ghost Light

Big Finish production codes

• 6C/A: The Land of the Dead
• 6C/B: Winter for the Adept
• 6C/C: The Mutant Phase
• 6C/D: Primeval
• 6C/E: Spare Parts
• 6C/F: Creatures of Beauty
• 6C/G: The Game
• 6C/H: Circular Time
• 6E/A: Omega
• 6P/A: Phantasmagoria
• 6P/B: Loups-Garoux
• 6P/C: Singularity
• 6Q/A: Red Dawn
• 6Q/B: The Eye of the Scorpion
• 6Q/C: The Church and the Crown
• 6Q/D: Nekromanteia
• 6Q/E: The Axis of Insanity
• 6Q/F: The Roof of the World
• 6Q/G: Three's a Crowd
• 6Q/H: The Council of Nicaea
• 6Q/I: The Kingmaker
• 6Q/J: The Gathering
• 6W/A: Davros
• 6Y/A: Year of the Pig
• 6Z/A: Whispers of Terror
• 6Z/B: ...ish
• 6Z/C: The Reaping
• 7C/A: The Marian Conspiracy
• 7C/B: The Spectre of Lanyon Moor
• 7C/C: The Apocalypse Element
• 7C/D: Bloodtide
• 7C/E: Project: Twilight
• 7C/F: The Sandman
• 7C/G: Jubilee
• 7C/H: Doctor Who and the Pirates
• 7C/K: Arrangements for War
• 7C/J: Project: Lazarus
• 7C/L: Medicinal Purposes
• 7C/MA: Pier Pressure
• 7C/MB: The Nowhere Place
• 7C/R: The One Doctor
• 7C/S: The Juggernauts
• 7C/T: Catch-1782
• 7C/U: Thicker Than Water
• 7D/A: Unregenerate!
• 7D/B: Red
• 7E/A: Bang-Bang-A-Boom!
• 7E/B: Flip-Flop
• 7F/A: The Fires of Vulcan
• 7R: The Fearmonger
• 7S: The Genocide Machine
• 7T: Dust Breeding
• 7U: Colditz
• 7V: The Rapture
• 7W: The Harvest
• 7W/A: Dreamtime
• 7W/B: Live 34
• 7W/C: Night Thoughts
• 7W/D: The Settling
• 7W/E: No Man's Land
• 7W/F: Nocturne
• 7X: Project: Lazarus
• 7Y: Master
• 7Z: The Sirens of Time
• 8B: Storm Warning
• 8C: Sword of Orion
• 8D: The Stones of Venice
• 8E: Minuet in Hell
• 8F: Invaders from Mars
• 8G: The Chimes of Midnight
• 8H: Seasons of Fear
• 8J: Embrace the Darkness
• 8K: The Time of the Daleks
• 8L: Neverland
• 8L: Zagreus
• 8M: Scherzo
• 8P: The Creed of the Kromon
• 8Q: The Natural History of Fear
• 8R: The Twilight Kingdom
• 8S: Faith Stealer
• 8T: The Last
• 8U: Caerdroia
• 8V: The Next Life
• 8W: Terror Firma
• 8X: Scaredy Cat
• 8Y: Other Lives
• 8Y/A: Time Works
• 8Y/B: Something Inside
• 8Y/C: Memory Lane