SW5 Earls Court: why this London postcode has the number 5

After Clapham, before Fulham

Earls Court is SW5 because of the alphabet. SW1 is the South Western district office, and in the Post Office's list of March 1917 the offices after it follow by name: Earls Court comes after Clapham (SW4) and before Fulham (SW6).

See SW5 on the map