Real-life Labour MP (Member of Parliament) John Stonehouse faked his own suicide in exactly the same way as Reginald Perrin - in the summer of 1974 he left his clothes on a beach in Miami and disappeared. However this was pure coincidence: David Nobbs wrote his novel "The Death of Reginald Perrin" early in 1974, before Stonehouse disappeared (so Nobbs couldn't have based the novel on Stonehouse's disappearance) but the novel wasn't published until 1975, after the MP vanished (so Stonehouse couldn't have got ideas for his disappearance by reading the novel). It became known as "Doing a Reggie", a phrase Nobbs remained unhappy about.
According to Tim Preece, people were sacked from the series because they couldn't work with the notoriously difficult star Leonard Rossiter. Preece, himself, left after series 2, replaced by Leslie Schofield as lugubrious son-in-law Tom.
Creator David Nobbs originally wanted Ronnie Barker to play Reginald Perrin, having written a lot of material for The Two Ronnies (1971). Barker (a self-confessed fan of the original "Death of Reginald Perrin" book) was, understandably, too busy with his commitment to that series and Porridge (1974) to be able to fit this into his schedule.
Veggie Perrins restaurant in Plymouth UK is named in tribute. It was officially opened by John Barron (CJ).
The streets in Reggie Perrin's neighbourhood, the signs for which he is regularly seen walking by to and from work - Wordsworth Drive," "Tennyson Avenue" and "Coleridge Close" (with the Perrins at number 12) - are named after the famous British 19th century poets, William Wordsworth, Alfred Lord Tennyson and Samuel Taylor Coleridge. In the novel, the Perrins live on "the Poets Estate". In the last episode of the series, when Reginald Perrin has taken another executive job in a large corporation, like the one he had at the beginning of the series, the street signs when he walks to work now read Liebnitz Drive, Bertrand Russell Rise and Schopenhauer Grove. These streets are named after the philosophers Gottfried Leibniz, Lord Bertrand Russell and Arthur Schopenhauer.