He was later moved to Swanzy Trading Company where he worked as a stenographer typist until 1927, when he returned to Sekondi.
In Sekondi, he worked with a firm of general merchants; Pickerings & Bethod, for two and a half years.
Inkumsah trained as a pharmacist from 1931 to 1934 and in December 1934 he opened his own business; the Asfordinks Drug Store in Sekondi.
Two years later he was elected a member of parliament for the Shama Ahanta constituency on the ticket of the CPP.
[15] He served in this capacity until 1965 when he was appointed Minister for Interior[16] and the first deputy speaker of the 1965 parliament, which lasted until 21 February, 1966.