Chisholm began work as a civil servant in 1990, working at the Department of Trade and Industry and Office of Fair Trading until 1997. He specialised in competition policy and the media, communications and financial services sectors. He then worked for three years for Pearson plc and the Financial Times, before spending some years working for technology companies, eCountries Inc and Ecceleration Ltd. He also founded ran Heritage Bulbs, a company specialising in the provision of rare and historic bulbs. In 2007 Chisholm was appointed as a commissioner of the Commission for Communications Regulation in Ireland, becoming its chair in February 2010. He left the role to become the first chief executive of the Competition and Markets Authority in the United Kingdom, with his appointment announced on 8 January 2013. The Competitions and Markets Authority was formally launched on 1 October 2013 and became fully operational on 1 April 2014. It brought together the most of the responsibilities of the former OFT and the former Competition Commission. Chisholm, after taking up his post, was responsible for merging these two bodies and streamlining their operations. In 2014, the CMA began an inquiry into the banking sector, which was opposed by major banks. The authority found that HSBC and First Trust Bank had broken competition rules. During a talk to the Institute of Directors, he defended the existence of regulators because "some market participants can ruin it for everybody" and that Bitcoin provided "welcome competition". In 2015, Chisholm wrote in a Financial Times article that proposed taxi regulations by Transport for London, following protests against ride-sharing firm Uber, would "artificially restrict competition". In 2016 he announced a CMA report that advocated abolishing passenger rail franchising to allow different companies to run services on the same routes.
Permanent secretary roles
Chisholm was appointed as permanent secretary to the Department of Energy and Climate Change in 2016, and continued as permanent secretary for the Department for Business, Energy and Industrial Strategy after it was created nine days later in September 2016 by merging DECC and the Department for Business, Innovation and Skills. His appointment was criticised by Stephen Fitzpatrick, the founder of OVO Energy, who said that a CMA inquiry into the energy industry that was run while he was chair was "subjected to lobbying from the big six" that resulted in reforms that The Times described as "watered down". The review opposed the introduction of energy price caps, which BEIS introduced in 2019 while Chisholm was its permanent secretary. Civil service unions wrote to him in 2018 about the conduct of Claire Perry O'Neill, a minister in the BEIS who had been accused of swearing and screaming at civil servants. In April 2020 he was appointed as chief operating officer of the civil service and Cabinet Office Permanent Secretary, succeeding John Manzoni who had served as chief executive of the civil service and Cabinet Office Permanent Secretary. The role, as the civil service's "second in command", includes leading reform of the civil service and advising on the COVID-19 pandemic. He began the new role on 14 April 2020.
Personal life
Chisholm married Eliza Pakenham, daughter of the historian, Thomas Pakenham and granddaughter of Frank Pakenham, 7th Earl of Longford, in 1993. They have three sons and live in London. He has been a trustee of Breadline Africa, an international charity, since 2003, and served as its deputy chair.