After graduating with a 2:2, Knight moved to London to find work, doing a variety of jobs before finding a job on a local newspaper. He moved up in journalism over the intervening years, working for the BBC as personal finance and consumer affairs reporter for five years until 2007, working across online, TV and radio. In 2007 he became the Money and Property Editor of The Independent on Sunday. In April 2015, Knight was criticised for a book he authored on tax avoidance. In his 2004 book, 'Wills, Probate and Inheritance Tax for Dummies', Knight "sets out ways that hardworking parents can pass on the graft of a lifetime" to their children. In the book, he is critical of the system of Inheritance Tax that existed at the point of publishing. He distinguished between personal tax avoidance, which he advised families on, and the "aggressive tax avoidance" of some multinational companies.
Political career
Elections
In 2014, Knight was selected to be the Conservative candidate for Solihull, a former Conservative safe seat which had been won by the Liberal Democrats in the 2005 General Election. At the 2015 general election Knight won the seat back for the Conservatives with a majority of 12,902, after an 11.9 per cent swing towards the Conservatives. Prior to the 2016 referendum on the UK's membership within the European Union, Knight campaigned to remain but now backs the Conservative Party policy of exiting the EU. Knight defended his seat at the 2017 general election and was returned with an increased majority. Knight once again defended his seat during the 2019 General Election. He once again increased his majority, this time to 21,273. The Liberal Democrats were again pushed into third place by Labour.
Government
In January 2018, Knight was appointed Parliamentary Private Secretary at the Ministry of Justice providing support to Ministers. In September 2018 he moved to the Department for Work and Pensions before moving to HM Treasury in January 2019. Knight is a passionate animal rights advocate and called for CCTV in slaughter houses before it was Government policy. Knight also serves as the Prime Ministerial Trade Envoy to Mongolia, where he forms part of a network of parliamentarians with the role to strengthen relations with foreign countries, and aide British businesses in accessing foreign markets. In April 2018, Knight made his first visit to the country as Trade Envoy. Knight is due to make his second visit in September 2018.