Sefton Stockford Careless [commonly known as Stockford Careless, and as Sefton S. Careless] was born on 1 January 1898 and was articled to to Healing and Overbury in Cheltenham, Essex. He also attended the Architectural Association in London. He practised as an architect in Middlesex, England from the early 1920s onwards. In the late 1920s he was in partnership with Joseph John Crowe (1883-1967) in the London-based architectural practice Crowe & Careless
Careless was elected an Associate of the Royal Institute of British Architects (ARIBA) in 1924 and a Fellow of the Royal Institute of British Architects (FRIBA) in 1935
Careless's address was given as Cotswold, Pinner Hill, Middlesex in 1926 and 1930; and 142 Leckhampton Road, Cheltenham, Gloucestershire in 1939. He died on 30 June 1962. His death was registered in Stroud, Gloucestershire.