Calculator · financial year 2026

Corporation Tax calculator (FY2026)

For financial year 2026 (1 April 2026 to 31 March 2027) a UK company pays Corporation Tax at 19% on taxable profits up to £50,000, 25% above £250,000, and a rate that rises gradually between the two through marginal relief. The limits are shared between associated companies and reduced for accounting periods shorter than 12 months. Enter the figures below for an estimate of the tax and the effective rate.

£

Profits chargeable to Corporation Tax after allowable deductions. Not the same as accounting profit.

Companies under common control during the period, not counting this one. Enter 0 if none.

12 for a normal year. A shorter period reduces the limits in proportion.

Figures update as you type. Nothing is sent anywhere; the arithmetic runs in your browser.

Enter the figures to see the result.

Estimate for financial year 2026, simple case. Nella provides financial information and education, not accounting or tax advice. Nella shows you the numbers. When a question needs professional judgement, such as a filing or a tax decision, Nella says so and points you to a qualified accountant.

How it is worked out

The arithmetic, stated plainly.

Limits

Lower limit £50,000 and upper limit £250,000, each divided by (associated companies + 1) and multiplied by months ÷ 12 for a short period.

Below the lower limit

Tax is profits × 19%.

Above the upper limit

Tax is profits × 25%.

Between the limits

Tax is profits × 25% minus marginal relief, where marginal relief is (upper limit − profits) × 3/200. The effective rate rises from 19% to 25% across the band.

What it does not cover

  • This is the simple case: no exempt distributions received (which raise augmented profits and reduce relief), no ring-fence profits, and an accounting period wholly within FY2026. Rates are unchanged since FY2023, so a period straddling 1 April 2026 uses the same figures.
  • Associated companies are counted under HMRC's rules, which look at control, not just shareholding. A qualified accountant confirms the count.
  • The result is an estimate of the liability, not the amount due on a given date. Payment is due 9 months and 1 day after the period end for companies below the instalment thresholds.

Sources

Related reading

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FAQ

Questions people ask

What are the Corporation Tax rates for 2026/27?
For financial year 2026 (1 April 2026 to 31 March 2027): 19% on taxable profits up to £50,000, 25% above £250,000, and marginal relief in between. Source: GOV.UK Corporation Tax rates.
How is marginal relief calculated?
Marginal relief is (upper limit − augmented profits) × 3/200, deducted from tax at the main rate. For a company with no exempt distributions, augmented profits equal taxable profits. The effect is an effective marginal rate of 26.5% on each pound between £50,000 and £250,000.
What counts as an associated company?
Broadly, another company under the same control at any point in the period. The £50,000 and £250,000 limits are divided by the number of associated companies plus one. Dormant companies are usually ignored.
When is the tax due?
For companies with profits of £1.5 million or less, 9 months and 1 day after the end of the accounting period. The CT600 return is due 12 months after the period end. Larger companies pay by quarterly instalments.
Does Nella calculate Corporation Tax?
No. Nella keeps your filing and payment dates in view and shows the profit figures from your books. The computation and the return are prepared by your accountant.