Hills received a commission as a lieutenant in the Royal Engineers on 5 July 1884, and was promoted to captain on 1 April 1893.Hart′s Army list, 1902 He worked as an instructor at the Royal School of Military Engineering at Chatham, later transferring to surveying duties as a member of the General Staff. In September 1900 he was appointed deputy assistant adjutant general (DAAG) at the War Office, and promotion to major followed on 25 July 1901. He was engaged in the British tribunal to arbitrate the Chile-Argentina boundary dispute. For this service he was appointed a Companion of the Order of St Michael and St George (CMG) in December 1902.
