Information about officers during this time can be found in series WO 339. Records about Territorial Army officers is held in series WO 374. To find out whether we hold documents concerning the person in whom you are interested, search the Catalogue entering the surname in which you are interested, e.g. Smithers, as a keyword, with WO 339 or WO 374 as the series code reference.

British Army Officers' Records: First World War 1914-1918

William Spencer, Army Service Records of the First World War (PRO, 2001)