King Edward Building in the City of London was London's main Post Office for most of the 20th century and also the main sorting office for the London EC postal area and for overseas mail. Designed by Sir Henry Tanner, it was opened in 1910 and closed in the 1990s.

The General Post Office (GPO) was the state postal system and telecommunications carrier of the United Kingdom until 1969. Established in England in the 17th century, the GPO was a state monopoly covering the dispatch of items from a specific sender to a specific receiver ; it was overseen by a Government minister, the Postmaster General. Over time its remit was extended to Scotland and Ireland, and across parts of the British Empire.