Corporation Tax Calculator
Calculate your company’s Corporation Tax liability including marginal relief
Corporation Tax
£17,450
Effective rate
21.8%
19% small · 25% main
Profit after tax
£62,550
Marginal relief
£2,550
Where your profit goes
Taxable profit
£80,000
Corporation Tax
21.8%
£17,450
Marginal relief included
£2,550
Profit after tax
78.2%
£62,550
Amount
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Frequently Asked Questions
What is the current UK Corporation Tax rate?
From April 2023, the main Corporation Tax rate is 25% for profits above £250,000. Companies with profits of £50,000 or less pay the small profits rate of 19%. Between these thresholds, marginal relief reduces the effective rate gradually from 25% to 19%.
What is marginal relief?
Marginal relief is a mechanism that gradually increases the effective Corporation Tax rate from 19% to 25% for companies with profits between £50,000 and £250,000. It prevents a cliff-edge where a small increase in profit would cause a large jump in tax. This calculator works it out automatically and shows the relief as a reduction in your bill.
How do associated companies affect Corporation Tax?
The £50,000 small profits limit and £250,000 main rate limit are divided equally between associated companies. For example, with 2 associated companies, the small profits limit becomes £25,000 each and the main rate limit becomes £125,000 each — so each company reaches the 25% rate at a lower profit level.
What counts as taxable profit?
Taxable profit for Corporation Tax includes trading profits, investment income and chargeable gains, after deducting allowable business expenses, capital allowances and any reliefs your company qualifies for. It usually differs from the accounting profit in your annual accounts, so use the figure from your tax computation for an accurate result.
When is Corporation Tax due?
Corporation Tax is normally due 9 months and 1 day after the end of your company’s accounting period. Large companies (profits above £1.5 million) must pay in quarterly instalments. Your CT600 return itself is due 12 months after the end of the accounting period.