Corporation tax calculator 2026/27 with marginal relief
Enter your company's taxable profit: the calculator applies 19%, 25% or marginal relief and shows the corporation tax, the effective rate and the profit left. With associated companies, short accounting periods and exempt dividends received. Free, no sign-up, in your browser.
Law as of 14 November 2026: corporation tax rates and limits for the financial years starting 1 April 2026 and 1 April 2027.
Your company's figures
Profit after allowable expenses, salaries, employer NI and capital allowances. Dividends you pay out are not deducted.
12 for a normal year. A first or last period can be shorter; a period cannot be longer than 12 months.
Other companies you or the same people control, wherever they are resident. A dormant company does not count.
Leave at 0 if your company receives no dividends. They are not taxed but can raise the rate.
Result
Corporation tax
£22,750.00
Effective rate 22.75%
- Lower limit£50,000.00
- Upper limit£250,000.00
- 25% of taxable profit£25,000.00
- Marginal relief-£2,250.00
- Corporation tax£22,750.00
- Profit after corporation tax£77,250.00
Your profits are between the limits: 25% minus marginal relief. Each extra £1 of profit here costs about 26.5p in corporation tax.
How we calculate
1. The limits for your company
The lower limit is £50,000 and the upper limit £250,000 for a 12-month accounting period. Both are divided by the number of associated companies plus one and reduced in proportion for a shorter period: 9 months gives £37,500 and £187,500 (Corporation Tax Act 2010 s. 18D).
2. Augmented profits
Taxable profit plus exempt dividends of a qualifying kind received from companies outside your group. This figure decides the rate; the tax itself is charged on the taxable profit only (Corporation Tax Act 2010 s. 18L).
3. Small profits rate or main rate
Augmented profits at or below the lower limit: 19% of taxable profit. At or above the upper limit: 25%. These rates apply to the financial years starting 1 April 2026 and 1 April 2027 across the UK (Finance Act 2026 ss. 11 and 12).
4. Marginal relief
In between, 25% of taxable profit minus marginal relief of 3/200 × (upper limit − augmented profits) × taxable profit ÷ augmented profits. Without dividends received, that is 3/200 of the gap to the upper limit (Corporation Tax Act 2010 s. 18B).
5. What is left
Taxable profit minus corporation tax. Dividends to shareholders can only come from this profit after tax (Companies Act 2006 s. 830).
What the calculator assumes
- Taxable profit means the profit after allowable expenses and capital allowances, for one accounting period of up to 12 months.
- The calculator reduces the limits by whole months, as HMRC's own example does. Strictly, HMRC counts days, so a period with part months can differ by a few pounds.
- The rates and limits are the same in the financial years starting 1 April 2026 and 1 April 2027, so a period that straddles 1 April needs no split.
- Profits above £1.5 million are paid in quarterly instalments; the calculator shows the tax, not the payment dates.
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Frequently asked questions
How much corporation tax do I pay on £100,000 profit?
£22,750 in 2026/27, for a 12-month period with no associated companies: 25% of £100,000 is £25,000, minus marginal relief of 3/200 × £150,000, which is £2,250. The effective rate is 22.75%.
What is marginal relief?
A reduction for profits between £50,000 and £250,000, so the rate rises gradually from 19% to 25%. Each extra pound in that band costs 26.5p in corporation tax.
How do associated companies change my corporation tax?
Each company divides the £50,000 and £250,000 limits by the number of associated companies plus one. With one associated company, £60,000 of profit pays £14,025 instead of £12,150.
My first accounting period is 9 months. What changes?
The limits shrink to 9/12: £37,500 and £187,500. HMRC's example: £55,000 of profit pays £13,750 minus £1,987.50 marginal relief, so £11,762.50.
Do dividends my company receives count?
Exempt dividends from companies outside your group are not taxed, but they are added to your profit to decide the rate. Dividends from a 51% subsidiary or parent are left out.
Information, not tax advice. The calculator does not replace advice from a qualified adviser. It neither stores nor sends your input.