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Corporation Tax Calculator 2026/27

See your exact Corporation Tax bill, your effective rate, and exactly where your profit sits on HMRC's marginal relief curve — instantly, visually, and for free.

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19%

Small profits rate, up to £50,000

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19–25%

Marginal relief, £50,000–£250,000

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25%

Main rate, above £250,000

Small Profits Rate (19%)

Marginal Relief (19–25%)

Main Rate (25%)

Your company's profit

Taxable profit for the accounting period (after allowable expenses, before tax)

Annual taxable profit

£0£300,000+

Where you sit on the tax curve

Your effective Corporation Tax rate as profit rises from £0 to £300k

19% small profits Marginal relief taper 25% main rate

Corporation Tax due

£0

Effective rate

— band

Taxable profit	£0
Corporation Tax	£0
Profit after tax	£0

How marginal relief works: between £50,000 and £250,000 profit, tax is calculated at the full 25% rate, then reduced by a marginal relief amount — this is what smooths the jump from 19% to 25% into a gradual slope instead of a cliff-edge.

How it's calculated

Three simple rules, one smooth curve

Corporation Tax isn't just a flat percentage — here's what actually determines your rate

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Profit up to £50,000

Taxed at the Small Profits Rate of 19% — flat, no calculation needed. This is the rate most small accounting practice clients fall into.

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Profit £50,000 – £250,000

Taxed at 25%, then reduced by Marginal Relief — a sliding discount calculated as (£250,000 − profit) × 3/200 — so your effective rate glides smoothly from 19% up to 25%.

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Profit above £250,000

Taxed at the Main Rate of 25% on the full amount — no relief applies above this threshold.

Common questions

Corporation Tax, explained simply

Why does my tax rate go above 19% before I even reach £250,000?▾

Marginal relief is designed so the jump from 19% to 25% isn't a sudden cliff-edge at one number — instead it rises gradually across the whole £50,000–£250,000 range. The closer your profit is to £250,000, the closer your effective rate gets to the full 25%.

Do the £50,000 and £250,000 thresholds change if I have more than one company?▾

Yes — if you have "associated companies" (broadly, companies under common control), both thresholds are divided by the total number of associated companies. This calculator assumes a single company with no associated companies; speak to your accountant if you have group structures.

Is Corporation Tax paid before or after my salary and dividends?▾

Before. Salary is a business expense deducted from profit first, which is why it lowers your Corporation Tax bill. Dividends are the opposite — they're paid out of profit that's already had Corporation Tax deducted, which is why dividend tax rates are lower than salary tax rates.

When is Corporation Tax due?▾

Normally 9 months and 1 day after the end of your accounting period — earlier than your filing deadline (12 months after period end), which often catches new directors out.

Rates used — 2026/27

Small Profits Rate 19% (profit up to £50,000), Main Rate 25% (profit above £250,000), Marginal Relief applies between the two using the standard fraction of 3/200. Thresholds assume a single company with no associated companies and a 12-month accounting period. Last verified against HMRC and GOV.UK publications: July 2026. Always confirm current figures at gov.uk — this tool is for general guidance, not personal tax advice.

Want your Corporation Tax handled, not just calculated?

Exuberant Global prepares and files Corporation Tax computations for 500+ UK accounting firms and their clients — accurate, on time, every period.

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