Martin trained as an accountant in London, initially working in the city before moving to the voluntary sector in 1995. He has been Finance Director for several medium size charities, most recently Ambitious About Autism, and currently combines working as a charities finance consultant with a second career as an artist.

He travels extensively and has lived and worked in Zambia, where he managed a honey factory, and India.

Martin became treasurer for Prisoners Abroad in 2018.