SW postcode area

The South Western (SW) postcode area in London comprises 20 postcode districts, divided into two operational regions: the South Western district (SW1-SW10) and the Battersea district (SW11-SW20). Unique for its location on both sides of the River Thames, it covers parts of nine London Boroughs. Mail sorting is handled at the Jubilee Mail Centre in Hounslow alongside other postcode areas like TW, KT, and GU.

Established in 1857 as the SW district, it absorbed parts of the short-lived S district in 1868, with the remainder going to SE. By 1917, it was divided into numbered districts. The head district, SW1, is significant for its dense population and use in geographic and cultural contexts. Notably, SW19 corresponds to Wimbledon, known for the Wimbledon Championships.

The area spans parts of Westminster, Kensington & Chelsea, Hammersmith & Fulham north of the Thames, and all of Wandsworth, with portions of Lambeth, Merton, Croydon, Richmond upon Thames, and Kingston upon Thames south of the river.