The company's head office was originally located at Rutland Street, Swansea, before it moved to the company's Russell Street offices (which also encompassed Brunswick garage). The Russell Street offices were destroyed in 1963 and replaced with new offices which opened in Apr 1964. Following the Swansea and District Transport Act 1935, and the replacement of tram services with buses, new accomodation was needed to house extra bus fleets. Land was purchased at Ravenhill to construct a 130 vehicle garage, which was completed in 1937. This was enlarged in 1939 by the addition of central workshops. The head office since 1985 has been Heol Gwyrosydd, adjoining Ravenhill works.
The garage at Brecon Road, Pontardawe, was built in 1928 but was replaced in 1960.
Eastland Road garage in Neath was built c1933. After the acquisition of Western Welsh Omnibus Company Limited, South Wales Transport used Neath Abbey, the former Western Welsh depot.
The Llanelly District Traction Company operated trolley and motor bus servicces in Llanelly [Llanelli]. In 1952 the South Wales Transport Company purchased the undertaking (including their Robinson Street depot) from the South Wales Electricity Board, and replaced the trolley buses with motor buses. Expansion of the Llanelli District Traction Premises at Robinson Street, Llanelli occurred when the freehold was purchased in 1965. The nearby premises in Copperwork Road were then closed.
Haverfordwest garage was transferred from Western Welsh in Mar 1972. Ammanford garage was acquired with the J James and Sons concern in 1962, and was rebuilt in 1968. Clarence Terrace was the United Welsh depot in Swansea, it came into South Wales Transport ownership in 1971. It was closed in 1981