Factual error: It's Christmas Eve 1925. Tommy and his son leave a mince pie for 'Santa and Rudolph', but there was no reindeer called Rudolph until the 1930s. The character's author hadn't even graduated by 1925, and only began writing a book about a red-nosed reindeer in 1939.
Factual error: Michael's impending 18th birthday is often mentioned as the time he becomes an adult and can make his own decisions. The age of majority in 1922 (and until 1970) was 21.
Episode #1.1 - S1-E1
Other mistake: When detective Campbell is making his speech to the officers, the board behind him has dates ranging from 1966 - 1975.
Episode #1.5 - S1-E5
Continuity mistake: When Tommy enters the office where Grace is working on the books he steps forward, leaving the door open, to draw a black star on her ledger. When he turns to leave the door is shut. (00:03:40)
Factual error: Kenya tea chests are marked KTDA. (Kenya Tea Development Agency). This did not come into being until the early 1970's.
Episode #3.5 - S3-E5
Factual error: All of Tommy's former men salute him. As a sergeant-major and not an officer he would never be saluted. This is drummed into all soldiers and they'd never do it, even in civilian life. Not only is it against regulations, but many NCOs would take it as an insult.
Episode #1.1 - S1-E1
Factual error: Thomas' record says he received the King's Medal for Gallantry in the First World War. There was no such medal. It would have been the Military Medal.
Factual error: In the House of Commons, Tommy refers to an unseen Tory MP as "My Right Honourable Friend" and as "the member for Epping." The former address is only used for Privy Councillors of the speaker's own party (Tommy is a Labour MP); MPs of other parties would be "the Right Honourable Gentleman." Winston Churchill was MP for Epping at the time and Tommy's secretary later says Churchill is in America, so he can't possibly be addressing the member for Epping.
Factual error: Jessie Eden is described as a shop steward. A shop steward is the senior part-time trade union official in a particular workshop or department, who also has an ordinary job in that shop. Jessie appears to be a full-time official and covers a number of factories. She would actually be referred to as a trade union organiser.
Factual error: In series 1, Sergeant Moss says he and most of his men served in the First World War, but none of them wear any medal ribbons. In series 2, Moss has suddenly acquired three medal ribbons, but they seem to be made-up and are not relevant to the First World War. From series 3, Moss is wearing the correct three service ribbons for the First World War.
Episode #2.3 - S2-E3
Other mistake: When the mother of a boy Arthur beats to death while boxing comes for revenge, she fires a single shot from a six-shot revolver at Arthur's head. Arthur then takes the revolver from her, ejecting 6 unspent bullets instead of 5. (00:28:24)
Episode #2.1 - S2-E1
Factual error: Season 2 covers 1921 to 1922. The car (YP8086) used in this episode was first registered 9th August 1926. (00:38:20 - 00:39:30)
Episode #2.2 - S2-E2
Continuity mistake: When Polly holds the gun against Tommy the hammer is pulled. Next shot it isn't. (00:45:52)
Continuity mistake: Tea leaves are visible to the top of the cup during the reading's close-ups, but the cup is clean each time the view switches to full screen. (00:29:30)
Factual error: Chief Inspector Campbell has been sent from Belfast. Belfast at the time was policed by the Royal Irish Constabulary, which had no rank of chief inspector.
Factual error: The fact Colonel Younger is black and this may be an issue socially is implied several times (meaning the series acknowledges his ethnicity), but it never seems to be seen as surprising that a black man is a colonel in the British Army in the first place. While there were a small handful of mixed-race junior officers in the army in the First World War, there were no post-war black regular officers (it was actually against regulations at the time) and no black officer would hold such a senior rank until long after the Second World War.
Character mistake: Several times Tommy addresses Sir Oswald Mosley as Mr Mosley instead of the correct Sir Oswald. Mosley never corrects him, which given his snobbishness portrayed throughout the series seems highly unlikely.
Other mistake: When Polly tells Ada about her two children being taken from her, she says Michael was 5 and "Sally" was 3. When she goes to the seance she says her daughter would be 18, but shortly after that Tommy finds Michael and he is 17. Also, when Tommy tells Polly that he found the records on her children, the daughter's name changes to "Anna."
Episode #3.6 - S3-E6
Continuity mistake: Michael picks up the cash from the table. After Polly speaks to Tommy she turns around to take the money out of Michael's hand; in the shot Michael is holding the cash in his lap with his jacket off, but when Polly takes the cash it shows her hand taking the money from Michael with him wearing his suit.
Episode #2.2 - S2-E2
Factual error: Tommy's service record quoted by Churchill says that he served throughout the war with the Warwickshire Yeomanry. But we already know that he was a tunneller on the Western Front. The Warwickshire Yeomanry was a cavalry regiment (which actually served in Egypt, Gallipoli and Palestine and finally as a machine-gun battalion on the Western Front at the very end of the war). All tunnellers served with the Royal Engineers.
