Hong Life CalculatorsRates for financial years 2023 to 2026
| Augmented profits | Rate |
|---|---|
| £50,000 or less | 19% small profits rate |
| £50,001 – £249,999 | 25% less marginal relief |
| £250,000 or more | 25% main rate |
How marginal relief is calculated
Marginal relief = 3/200 × (upper limit − augmented profits) × taxable total profits ÷ augmented profits. Tax = 25% of taxable profits − marginal relief.
Both limits are divided by the number of associated companies plus one, and reduced in proportion for an accounting period shorter than 12 months (days ÷ 365).
Example: profits £100,000, no associated companies → 25% = £25,000; relief = 0.015 × (£250,000 − £100,000) × 1 = £2,250; tax £22,750 (22.75%).
FAQ
Do I pay 19% or 25% Corporation Tax?
19% if your augmented profits are £50,000 or less, 25% if they are £250,000 or more, and a blended rate between the two through marginal relief.
When is Corporation Tax due?
Most small and medium companies pay in one sum after the end of the accounting period and file the CT600 return later; large companies pay in quarterly instalments. Check the exact dates for your company on GOV.UK.
How do associated companies change the limits?
The £50,000 and £250,000 limits are shared: with one associated company they become £25,000 and £125,000.
Sources (checked 10 November 2026): HMRC “Corporation Tax rates and allowances” (rates, limits, 3/200 standard fraction for 2023–2026); GOV.UK “Marginal Relief for Corporation Tax”; Corporation Tax Act 2010 s.18B. Estimate, not tax advice.