UK Corporation Tax Calculator 2026/27 – Marginal Relief (19% to 25%)
Estimate corporate income tax in the UK on any profit: tax due, effective rate and profit after tax, with the 25% headline rate and the reduced rates in force in September 2026.
The calculation runs in your browser: nothing you type is uploaded or stored. Results are estimates for planning, not tax advice. Check your own case with your adviser or the tax authority.
Corporate tax rules in the UK
19% on profits up to £50,000.00, 25% on profits above £250,000.00, and the main rate less marginal relief (standard fraction 3/200) in between
Financial year 2026 (1 April 2026 to 31 March 2027)
19% on profits up to GBP 50,000; 25% above GBP 250,000; marginal relief in between (effective marginal rate 26.5%)
Who qualifies for the lower rates
- Marginal relief = 3/200 x (upper limit - augmented profits) x (taxable profits / augmented profits); augmented profits include dividends from non-group companies.
- The GBP 50,000 and GBP 250,000 limits are divided by (1 + number of associated companies) and reduced pro rata for accounting periods shorter than 12 months.
- Rates, limits and fraction are unchanged for FY2023, FY2024, FY2025 and FY2026.
- Ring fence (oil and gas) profits and unit trusts/OEICs (20%) have different rates.
Local taxes and minimum taxes
No local corporate income tax.
Pillar Two multinational top-up tax and domestic top-up tax for groups >= EUR 750m not modelled.
Filing and payment
Return (CT600) within 12 months after the accounting period ends; tax due 9 months and 1 day after the period ends (large companies pay quarterly instalments)
How the calculation works
The calculator applies the rates in the order the law does: band by band where a country taxes profit in slices, or one rate to the whole profit where eligibility decides the rate. Surcharges are applied to the tax, local business taxes to the profit. The result is an estimate: it does not include loss relief, tax credits, deferred tax or group rules.
Frequently asked questions
What is the corporate tax rate in the UK?
19% on profits up to £50,000.00, 25% on profits above £250,000.00, and the main rate less marginal relief (standard fraction 3/200) in between
How much corporate tax is due on a profit of £100,000.00?
On a taxable profit of £100,000.00 this calculator estimates £22,750.00 of tax, an effective rate of 22.75%, before any credits, losses or local adjustments. Change the inputs above to model your own figures.
Who qualifies for the reduced rates?
Marginal relief = 3/200 x (upper limit - augmented profits) x (taxable profits / augmented profits); augmented profits include dividends from non-group companies. The GBP 50,000 and GBP 250,000 limits are divided by (1 + number of associated companies) and reduced pro rata for accounting periods shorter than 12 months. Rates, limits and fraction are unchanged for FY2023, FY2024, FY2025 and FY2026. Ring fence (oil and gas) profits and unit trusts/OEICs (20%) have different rates.
When is the corporate tax return due?
Return (CT600) within 12 months after the accounting period ends; tax due 9 months and 1 day after the period ends (large companies pay quarterly instalments)
Does the estimate include local taxes and minimum taxes?
No local corporate income tax. Pillar Two multinational top-up tax and domestic top-up tax for groups >= EUR 750m not modelled.
Is the result my exact tax bill?
No. It applies the statutory rates to the profit you enter. Your real bill depends on how taxable profit is computed (non-deductible costs, losses brought forward, allowances), on credits and on advance payments already made.
Are these rates up to date?
They were checked against HM Revenue & Customs (GOV.UK) and the other sources listed on this page on 30 September 2026. If a rate changes, type the new one into the rate field and the result updates at once.
Sources
- Rates and allowances: Corporation Tax (updated 1 April 2026) — HM Revenue & Customs (GOV.UK)
- Corporation Tax rates and reliefs — GOV.UK
- Marginal Relief for Corporation Tax — GOV.UK
- United Kingdom - Corporate - Tax administration (PwC Worldwide Tax Summaries) — PwC
Rates, bands and thresholds were checked against these sources on 30 September 2026. Tax rules change: if a rate has moved, edit it in the calculator above.
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