SW19 Wimbledon: why this London postcode has the number 19

Last in the alphabet, after Wandsworth

Wimbledon is SW19 because of the alphabet. SW11 is Battersea, a district office, and in the Post Office's list of March 1917 the offices after it follow by name: Wimbledon comes after Wandsworth (SW18), and is the last of them.

See SW19 on the map