After his return to India, Paul joined the Apeejay Group, which his father had founded. Destiny brought him to London in 1966 in search of treatment for his daughter Ambika, who was suffering from leukemia, and after her untimely death, he stayed on.

Lord Paul started his business in Britain in 1968. After acquiring one steel unit, he went on to acquire more units and founded the Caparo Group in 1978. Caparo developed into one of the leading producers of welded steel tube and spiral-welded pipes in the UK. In 1996, Lord Paul stepped down from the management of the Caparo Group and handed over the reins to his three sons. He has won several honours and awards. He wrote the biography of former Indian Prime Minister Indira Gandhi.

Currently British Ambassador for Overseas Business, Lord Paul is Chancellor of two universities-- the University of Westminster and the University of Wolverhampton. A philanthropist, Lord Paul donated one million pounds to the London Zoo to save it from closure in 1993.

He was also appointed Chairman of the Olympic Delivery Committee with the key task of providing infrastructure for the London Olympics 2012.