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Corporation Tax Calculator

Calculate your limited company's corporation tax for 2026/27 — including small profits rate, main rate and marginal relief.

📅 Tax Year 2026/27

🏢 Company Profits

£
This is your company's profit before tax. Revenue minus allowable expenses (including salary, employer NI, pension, depreciation via capital allowances).
If you have associated companies, the upper and lower limits are divided between them, which can mean higher rates apply to lower profits.

📊 Corporation Tax Calculation

Taxable Profits—
Rate Applied—
Corporation Tax Due—
Profit After Tax—
Effective Tax Rate—

📋 Corporation Tax Rates 2026/27

ProfitsRateDescription
Up to £50,00019%Small Profits Rate
£50,001 – £250,00019–25%Marginal Relief applies
Over £250,00025%Main Rate

Thresholds are divided by the number of associated companies. Marginal relief gradually increases the effective rate from 19% to 25% between the two limits.

⚠️ Disclaimer This is an estimate only. Corporation tax is complex — your actual liability depends on capital allowances, research & development relief, losses, and other adjustments. Always use a qualified accountant and file your CT600 with HMRC by the deadline.

📌 Rates sourced from Corporation Tax rates — verified for the 2026/27 tax year.

Frequently Asked Questions

What is the corporation tax rate for 2026/27?

The corporation tax rate depends on your company's profits. The small profits rate is 19% on profits up to £50,000. The main rate is 25% on profits above £250,000. For profits between £50,000 and £250,000, marginal relief applies — gradually increasing the effective rate from 19% to 25%.

What is corporation tax marginal relief?

Marginal relief is a taper that smoothly increases the corporation tax rate from 19% to 25% for companies with profits between £50,000 and £250,000. It is calculated as: (3/200) × (upper limit − profits). This is subtracted from the 25% main rate tax to give the actual tax due.

When do I pay corporation tax?

Corporation tax is due 9 months and 1 day after the end of your accounting period. For example, if your year ends 31 March 2025, tax is due by 1 January 2026. Large companies (profits over £1.5m) pay by quarterly instalments.

What are associated companies and how do they affect corporation tax?

An associated company is another company under the same control. The £50,000 lower limit and £250,000 upper limit for corporation tax rates are divided equally between associated companies. So with two associated companies, the small profits rate applies only up to £25,000 each.