The cast list gives Ben and Jerry's surnames as Rosenstern and Guildencranz. This is a reference to Rosencrantz and Guildernstern, two minor characters in Shakespeare's play Hamlet (2015). In Tom Stoppard's play of 1966 National Theatre Live: Rosencrantz & Guildenstern Are Dead (2017) he flips the plot and they become the major characters. In Stoppard's play they are like two halves of a single character and other characters in the play have trouble distinguishing which one is which; much like the hapless Ben and Jerry.
W1A is the first part of the post code (zip code in the US) of the former BBC broadcasting centre. The full code W1A 4WW is no longer in use.
The W1A theme tune was originally used for Johnny Morris' series "Animal Magic".
The show's creator John Morton announced at a preview screening for the third series that series three of W1A was likely to be the final one made.
The meeting room "Frankie Howerd", used for many of the meetings in the show and featuring a large black and white photo of Howerd, is named after Frankie Howerd, OBE (1917-1992) an English comedian and comic actor whose career spanned six decades known for directly addressing the camera and catchphrases such as "Oooh, no missus" and "Titter ye not".