John was educated at King Edward's School, Edgbaston, Birmingham and won the Rickard Prize for Arithmetic whilst there. Upon leaving, he won a scholarship to Magdalen College, Oxford, where he studied Natural Sciences, specializing in Atomic, Nuclear & Theoretical Physics, graduating in 1981.
He founded his first business (John Hemming & Co, now JHC plc) at the age of 23. This has grown to become a multi-million pound company and the leading provider of settlement systems to stockbrokers in the UK. John founded the first e-commerce operation (MarketNet) outside the USA in 1994. He also launched the world's first, banking, insurance, legal and stock-broking services on the Internet in 1995. He founded Music Mercia International (MMI), a music company in 1997. In 2000, he founded The Purchasing Agency (also known as SafeSimple.Com) - which competes with Visa and MasterCard.
His technical skills lie particularly in the areas of mathematics and programming. He is an accomplished cryptographer having devised a number of security and payment protocols. He was the first person outside the USA to implement the main SSL World Wide Web security protocol. He is one of the world's leading internet technical experts and programs in eight different programming languages.
John Hemming is the leader of the Liberal Democrats on Birmingham City Council and has been the Deputy Leader of the City Council. He was the party's candidate for Birmingham Yardley in 1992, 1997 and 2001. He won the Yardley seat from Labour in the 2005 Election with a majority of 2,672. He had been a Birmingham City Councillor since 1990 until standing down in 2007 to concentrate on serving his constituents as an MP.
John is a member of Friends of the Earth, Greenpeace and the Musician's Union. He was a drummer in a Heavy Metal Rock Group and plays jazz piano (having performed with Andy Hamilton and the Blue Notes and the John Patrick Quartet). He was a candidate for Britain's First Astronaut and speaks six languages.