The internal bracing of the fuselage of the O/400 military bomber made it unsuitable for long-term use as a civil transport, leading to redesign and the development of an aircraft identified originally as the Handley Page W/400 (H.P.16 in the 1924 designation system). This combined a fuselage of different construction, that would allow for up to eight pairs of forward facing seats with a central gangway, with V/1500 type reduced-span wings, V/1500 landing gear and power provided by two Rolls-Royce Eagle VIII engines. In this form the aircraft was flown for the first time on 22nd August 1919. Testing confirmed that the basic design was sound, but it was decided to incorporate refinements and more powerful engines in the production version, leading to the W.8 prototype (H.P.18 in the 1924 system). Powered by two 450 hp Napier Lion IB engines, the W.8 had a further reduction in wing span (from 85 to 75 ft) and some revision of the tail unit. This modified version was first flown on 2nd December 1919. On 4th May 1920 it was flown with a payload of 3,690 lb to a height of 14,030 ft, which qualified as a British record.
The W.8 was followed by four production W.8b aircraft, which had accommodation for 12 passengers in a well-glazed cabin, the pilot and co-pilot being seated in an open cockpit in the nose. Due to the Napier Lions being difficult to obtain, these aircraft reverted to the Rolls-Royce Eagle VIII powerplant, but these lower-powered engines meant that certification to carry only 12 passengers was given. Three of these aircraft were used by Handley Page Transport and one was supplied to the Belgian airline Sabena; subsequently, three more W.8b transports were licence-built for Sabena by SABCA in Belgium. The more powerful Rolls-Royce Eagle IX engine was fitted to the aircraft in 1923 and this version became the W.8c.
Subsequent versions of the same basic design included the W.8e (H.P.26) which introduced a third engine mounted in the nose of the fuselage. The nose mounted engine was a 360 hp Rolls-Royce Eagle IX and the two wing mounted engines were 230 hp Siddeley Pumas. One was built for Sabena by Handley Page and eight more were licence-built for that airline by SABCA. A similarly-powered W.8f Hamilton was completed for service with Imperial Airways, which also included a modified fin, and two more W.8f transports were later built by SABCA for service with Sabena. The W.8g was a Hamilton rebuilt in 1929 with two Rolls-Royce F.XIIA engines.
Other variants of this basic design included one H.P.27 W.9a Hampstead for Imperial Airways, powered initially by three 385 hp Armstrong Siddeley Jaguar radial engines and later by three 450 hp Bristol Jupiter VI radials, and this had accommodation for 14 passengers. The final civil version was the H.P.30 W.10, of which four were built in 1926 by Handley Page for Imperial Airways, and the last of these was not retired from service until 1933. They reverted to the twin-engine powerplant, comprising of two 450 hp Napier Lion IIB engines.