Howard was commissioned into the Essex Regiment as a second lieutenant on 1 December 1897. He served with the 1st battalion of his regiment in South Africa during the Second Boer War. The battalion was present at the operations around Colesberg in January 1900, following which he was promoted to lieutenant on 29 January 1900; then took part in the battle of Paardeberg (February 1900) and the subsequent march to Bloemfontein, during which he was aide-de-camp (ADC) to Brigadier General Theodore Stephenson. His battalion joined the force that subsequently went to occupy Pretoria, and took part in the engagement at the Vet River, and the battles of Diamond Hill (June 1900) and Belfast (August 1900). For his service in the war, he received the Distinguished Service Order (DSO) in the October 1902 South African honours list. After the war ended in June 1902, Howard stayed in South Africa as ADC to Stephenson, who was now Major-General in Command at Bloemfontein district.