High Quality Content by WIKIPEDIA articles! Corporation tax is a tax levied in the United Kingdom on the profits made by companies and on the profits of permanent establishments of non-UK resident companies and associations that trade in the EU. Prior to the tax`s enactment on 1 April 1965, companies and individuals paid the same income tax, with an additional profits tax levied on companies. The Finance Act 1965 replaced this structure for companies and associations with a single corporate tax, which borrowed its basic structure and rules from the income tax system. Since 1997, the UK`s Tax Law Rewrite Project has been modernising the UK`s tax legislation, starting with income tax, while the legislation imposing corporation tax has itself been amended; the rules governing income tax and corporation tax have thus diverged. Corporation tax is governed by the Income and Corporation Taxes Act 1988 (as amended).