The tube can be accessed on each side of the Balham High Road (A24); National Rail on the south side of the road leading east, where the track is on a mixture of light-brick high viaduct and earth embankment, quadruple track and on a brief east–west axis.

[citation needed] The original station was on the west side of Balham High Road; it was re-sited by the LB&SCR in 1863 as part of works to widen the line, and improve the route between East Croydon and Victoria.

[9] The lines through the station to Crystal Palace were electrified in 1911,[12][page needed] by means of the LB&SCR 'Elevated Electric' overhead system.

Work on electrifying the remaining services through the station had begun in 1913 but was interrupted by the First World War and not completed until 1925.

In 1925 the Southern Railway decided to adopt a third rail electrification system and the lines through the station were converted between June 1928 and September 1929.

[14] When sectorisation was introduced in the 1980s, the national rail lines were served by Network SouthEast until the privatisation of the British Railways in the 1990s to the Connex South Central franchise, replaced by the current operator in 2000.

They were conceived and constructed by Christine Thomas and Julia Barton and installed in 1991 for Wandsworth Borough Council.

[7] The station has entrances on the east and west sides of Balham High Road linked by a pedestrian subway.

[citation needed] During the Second World War, Balham was one of many deep tube stations designated for use as a civilian air raid shelter.

On the evening of 14 October 1940, a 1,400 kg semi-armour piercing fragmentation bomb fell on the road above the northern end of the platform tunnels,[19][20] creating a large crater into which an out-of-service bus then crashed.

The damage at track level closed the line to traffic between Tooting Bec and Clapham Common.

[24] This second plaque was again replaced with an official memorial stone in Welsh slate commissioned by London Underground and that was unveiled on 14 October 2016.