 Iwi was admitted as a solicitor in 1927, and served as a Law Society examiner from 1938 to 1962.He was an indefatigable writer to the Editor of "The Times", usually on anomalies in the law that had been overlooked.In 1937 Iwi called for the creation of a Commonwealth Court, which would replace the judicial functions of the House of Lords and become the court of final appeal in UK cases rather than the Privy Council.