What is the rate of Corporation Tax? How does marginal relief work? Which companies pay the main rate of Corporation Tax? Which companies pay the small profits rate of Corporation Tax? How do I calculate Corporation Tax? 

This is a freeview 'At a glance' guide to Corporation Tax rates, including marginal relief. 

Corporation Tax rates for companies


Profit bands




2023-24 and


Small profits rate 0 - 50,000 19% 19%
Marginal rate 50,001 - 250,000 26.5% 19%
Main rate >250,000 25% 19%
Fraction   3/200 n/a


  • The company tax year, known as a Financial Year, starts on 1 April. 
  • The main rate of Corporation Tax, for Financial Years 2017-2022, for all non-ring fence profits is 19%.
    • Ring fence profits are those from oil extraction or oil rights in the UK or UK continental shelf. 

From 1 April 2023:

  • The main rate of Corporation Tax increased from 19% to 25%.
    • The small profits rate (19%) applies to single companies with Augmented profits of less than £50,000.
    • The main rate (25%) applies to single companies with Augmented profits of more than £250,000.
    • The main rate (25%) also applies to single companies with Augmented profits between £50,000 and £250,000, but marginal relief will be given. 
  • The £50,000 threshold is known as the lower limit and the £250,000 threshold is known as the upper limit.
    • The upper and lower limits are apportioned according to the number of companies which are Associated for Corporation Tax.
    • The limits are also apportioned for short accounting periods.
  • Close Investment Holding Companies (CIHCs) pay Corporation Tax at the main rate regardless of their level of profits.

The marginal relief calculation from 1 April 2023

When adjusted 'Augmented' profits fall between the Lower and Upper limits, Marginal relief is given by reducing the 25% Corporation Tax charge by: 

Fraction x (Upper Limit – Augmented Profits) x Taxable Total Profits/Augmented Profits 

In the legislation it is described as: F x (U-A) x N/A 

  • U = Upper limit 
  • A = Augmented profits
  • N = Taxable total profits
  • F = Standard marginal relief fraction (3/200)

What are Augmented profits?

How to calculate Corporation Tax?

Earlier years Corporation Tax rates


Profit bands




2015-16 to
2014-15 2013-14 2012-13 2011-12 2010-11
Small 0 - 300,000 20% 20% 20% 20% 20% 21%
Marginal 300,001 - 1,500,000 20% 21.25% 23.75% 25% 27.5% 29.75%
Main >1,500,000  20% 21% 23% 24% 26% 28%
Fraction   n/a 1/400 3/400 1/100 3/200 7/400

Useful guides on this topic 

A new company? Start here
'At a glance' freeview guide is essential reading for anyone thinking about starting up a new company. 

An existing company? Start here...
You have started to run your business through your company. What about Corporation Tax compliance? Does your company have special tax rules that apply?

Sole trader v. limited company: Tax differences & savings (2024/25)
Is it better from both a tax and legal point of view to run your business as a sole trader or as a company? Are there tax advantages in running a business as a company? What legal protections apply?

Associated companies & tests for control
What are the tax effects of associated companies? What is an associated company? How do the control tests work?

Close Investment Holding Companies
When does a close company become a Close Investment Holding Company? What are the consequences?

Close companies: Definitions & control
This guide goes over basic definitions. When is a company deemed 'close' and what constitutes control?


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