In Inspector Morse (1987), Morse and Lewis worked for the Thames Valley Police - the actual police force that is responsible for this part of the country. However in Inspector Lewis (2006), Lewis and Hathaway work for the fictitious Oxfordshire Police Force because the producers were not allowed to use the name, uniforms, or emblems of Thames Valley Police and could not film at St Aldate's Police Station. It is thought that this is due either to Home Office security restrictions in connection with the Iraq war or because of a lack of cooperation by a newly appointed Chief Constable.
The stories for Series 7-9 are each shown as two 45-min parts on consecutive weeks in the UK. This is in contrast to Series 1-6 stories, which are shown as single 90-min episodes. Therefore, Series 7-9 are filmed in blocks of two 45-min episodes.
In each episode of season 4 one of the main suspects is played by an actor who has also starred as a famous fictional detective: 1. "The Dead of Winter" - Nathaniel Parker (Inspector Lynley, Inspector Lynley Mysteries) 2. "Dark Matter" - Warren Clarke (Det Supt Andy Dalziel, Dalziel & Pascoe) 3. "Your Sudden Death Question" - Alan Davies (Jonathan Creek) 4. "Falling Darkness" - Rupert Graves (Inspector Lestrade, Sherlock)
James Hathaway's father Phillip is introduced as a character in Endeavor Season 3 Episode 3 "Prey" as a young man. He is shown as a hand working on the estate and interacts with a young Inspector Morse and Detective Inspector Thursday.