At the beginning of the Boer War the strength of this corps was three officers and eighty-nine other ranks. They made up one company of the 24th Middlesex (Post Office) Rifle Volunteers. These men, like all the 24th Middlesex, were drawn from the London Post Office. They were those who had been specially enlisted for a period of six years in the Army Reserve to render them available for foreign service. This original force, which proceeded to the seat of war in October 1899, soon became totally inadequate to the growing needs of the Army.

Later reinforcements were drawn from the provincial postal services of Great Britain, and even from those of Canada, Australia, Cape Colony and India. The greatest strength attained at the height of the campaign was ten officers, a warrant officer, and 396 other ranks. In addition there were twenty civilian clerks and 100 soldiers attached for orderly duties. They suffered 46 fatalities from wounds and disease. 

The names of the men who served in the regiment are listed below