The standard corporate tax rate is 25% (increased from 19% effective 1 April 2023).

Further, effective 1 April 2023, a small profits rate of 19% is introduced for companies with profits of GBP 50,000 or less; whereas, the standard 25% rate applies to companies with profits between GBP 50,000 and GBP 250,000 with marginal relief.

The main rate is reduced to 24% for the financial year starting 1 April 2012, 23% for the financial year starting 1 April 2013, 21% for the financial year starting 1 April 2014 and 20% for the financial year starting 1 April 2015. A reduced rate of 20% applied to small companies (i.e. companies with taxable profits of less than GBP 300,000) up to 1 April 2015, when the standard rate was reduced to 20%. Companies with taxable profits between GBP 300,000 and GBP 1.5 million prior to 1 April 2015 were effectively taxed on a sliding scale at an average rate between the main rate and the small profits rate.
Under the Finance (No. 2) Act 2015, the UK will reduce the main rate of corporation tax to 19% for the 2017, 2018 and 2019 financial years and to 18% for the 2020 financial year.