Calculate your UK limited company corporation tax liability including marginal relief. Updated for the 2026/27 financial year.
This calculator estimates the Corporation Tax liability for a UK limited company. It applies the correct marginal rate based on your taxable profits, including the small profits rate (19%) for profits up to £50,000 and the main rate (25%) for profits over £250,000.
Note: Based on 2026/27 HMRC Corporation Tax rates. Marginal relief applies to profits between £50,000 and £250,000.
Rates shown are for the 2026/27 tax year. The small profits rate (19%) applies to profits up to £50,000 and the main rate (25%) to profits over £250,000. Marginal relief applies between these thresholds. Associated companies reduce the thresholds proportionally.
| Profit | Rate |
|---|---|
| £0 – £50,000 | 19% |
| £50,001 – £250,000 | Marginal |
| Over £250,000 | 25% |
How your tax changes as profit grows (current accounting period and associated companies)
Companies with profits of £50,000 or less pay corporation tax at 19%. This rate applies to the full profit — there is no marginal relief at this level.
Profits between £50,001 and £250,000 attract marginal relief, which tapers the effective rate between 19% and 25%. The formula is: (£250,000 − profit) × 3/200.
If your company has associated companies, the £50,000 and £250,000 thresholds are divided equally between them. This can push you into a higher rate band.