How it works
19% below the small-profits limit; 25% above the main limit. Between them, tax = 25% of profit − 3/200 × (upper limit − profit).
A worked example
A standalone company with £100,000 taxable profits pays £22,750 after £2,250 marginal relief.
What to keep in mind
Assumes a 12-month accounting period, UK-resident non-ring-fence company, augmented profits equal taxable profits, and eligibility for the small-profits rate. Limits divide by total associated companies including this one. Excludes distributions, short periods and close investment-holding companies.
Corporation Tax rates
Companies with profits of £50,000 or less pay the small profits rate of 19%. Companies with profits above £250,000 pay the main rate of 25%. Profits in between pay 25% with marginal relief, which gradually raises the effective rate from 19% to 25%.
Worked examples
£40,000 of profit means £7,600 of tax (19%). £100,000 means £22,750 after marginal relief, an effective rate of 22.75%. £300,000 means £75,000 (25%).
Associated companies
The £50,000 and £250,000 limits are shared between associated companies. With one associated company, each limit is halved, so more profit falls into the higher rates.
Frequently asked questions
What is the Corporation Tax rate?
19% on profits up to £50,000, 25% on profits over £250,000, and an effective rate between the two with marginal relief.
When is Corporation Tax due?
For most companies, 9 months and 1 day after the end of the accounting period.
Do associated companies affect the result?
Yes. The £50,000 and £250,000 limits are divided by the number of associated companies, including the company being calculated.
Sources & rates
Rates checked on 7 October 2026.
For general information and planning, not personalised financial or tax advice. Verify important decisions with a qualified adviser.