Klyberg served in the British Army to satisfy the required National Service. On 19 December 1953, he was commissioned into the Buffs (Royal East Kent Regiment) as a second lieutenant.[4] On 16 May 1955, he transferred to the Territorial Army as a second lieutenant with seniority in that rank from 19 December 1953; this ended his full-time military service and began the required part-time period of service.[5] On 21 August 1955, he was promoted to lieutenant.[6] On 23 October 1958, he transferred to the Territorial Army Reserve of Officers; this ended his military service and began his call up liability.[7] He resigned his commission on 9 July 1960, and this ended his call up liability.[8]