Outside the game, Cullum was apprenticed to Benham & Co in his hometown as a teenager (his Dad wouldn't let him sign full-time professional saying 'no footballer has ever earned good money'. After becoming assistant works manager in his thirties he took a similar role next door at QB Printers, before setting up a typesetting business Wolf Composition in Watford in 1970. In later working life, he was managing director of another typesetting business, Santype International in Salisbury, building it to be the largest technical typesetting company in the country. He died aged 81 on 9 April 2012. He had three sons, Steven, Gary and Dale.