Corporation Tax Calculator UK
Calculate UK corporation tax with the 19% small profits rate, 25% main rate and marginal relief.
🇬🇧 Built for United Kingdom
How to use the Corporation Tax Calculator UK
- Enter taxable profit (12 months).
- Enter number of associated companies – Limits are divided by (associated companies + 1).
- Your results update instantly: lo, hi, corporation tax, effective rate.
UK corporation tax rates
| Profit | Rate |
|---|---|
| £0 – £50,000 | 19% (small profits rate) |
| £50,001 – £249,999 | 25% less marginal relief |
| £250,000+ | 25% (main rate) |
Marginal relief formula
Tax = Profit × 25% − (£250,000 − Profit) × 3/200
Example: £120,000 profit → £30,000 − £1,950 = £28,050 (23.4% effective). Profits in the marginal band are effectively taxed at 26.5%.
Associated companies
If your company has associated companies (under common control), the £50,000 and £250,000 limits are divided between them. Short accounting periods reduce the limits proportionally.
Frequently asked questions
When is corporation tax due?
Nine months and one day after the end of your accounting period for most companies.
What is the effective rate in the marginal band?
Each extra pound of profit between £50,000 and £250,000 is taxed at 26.5%.
Last updated 15 November 2026. Results are estimates for general information and are not financial, tax, legal or medical advice.
