Corporation Tax Marginal Rates and Useful Calculator

The main rate of corporation tax (CT) jumped from 19% to 25% with effect from 1 April 2023 and will be a substantial increase in the tax burden to most companies.

Full details of the rates and rules relating to Corporation Tax are at https://www.gov.uk/topic/business-tax/corporation-tax . If profits are under £250,000 you should look to see if there are any associated companies (which change the thresholds below), but from 1 April 2023 the Corporation Tax rate changes to:

  • 19% for taxable profits below £50,000 (small profit rate)
  • 25% for taxable profits above £250,000 (main rate)

Marginal Relief provides a gradual increase in Corporation Tax rate between the small profits rate and the main rate — this allows you to reduce your rate from the 25% main rate.

A useful calculator is available at the link below;

Corporation Tax Calculator

Please contact us if you would like further advise on the new rates.

Recent Posts

Key accounting practices for managing business debt effectively

Wealth transfer strategies for high-net-worth individuals

News Round Up: December 2025