The 'H' series, following directly on from the 'F' series in late 1918, consists largely of orders that were cut or cancelled within a few months of being placed, due to the cessation of hostilities
British Military Aircraft Serials 1911-1979, Bruce Robertson (PSL, 1979)
The D.H.9 and 9A allocations in the 'H' series were as follows:
D.H.9
H3196-3395 - cancelled order with National Aircraft Factory No. 2
H4320-4369 - cancelled order placed with Berwick & Co.
H7563-7612 - cancelled order placed with G. & J. Weir Ltd.
H7913-8112 - ordered from Crossley Motors Ltd. 25.9.18 (No. 4 NAF)
H9113-9412 - built by the Aircraft Manufacturing Co. Ltd., Hendon
D.H.9/9A
H4216-4315 - ordered from A.M.C.
D.H.9A
H1-200 - built by A.M.C.
H3396-3545 - built by Westland Aircraft Works, Yeovil
H3546-3795 - built by the Vulcan Motor & Engineering Co. (up to H3559 confirmed delivered)