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Corporation Tax Liability Calculator (UK)

Estimate UK company Corporation Tax liability using 19% and 25% rates, Marginal Relief, accounting-period adjustments and associated-company limits.

Planning estimate only. Uses rates confirmed for periods from 1 April 2023 through 31 March 2027. It assumes a UK-resident company that is not a close investment-holding company and has no ring-fence profits. Check the notes and HMRC sources below before relying on the result.

Important: This tool provides an estimate for general information and planning. It is not financial, tax, investment, or lending advice. Check current rules, rates, fees, and provider terms before making an important decision.
Company and accounting-period details

After allowable expenses, losses, capital allowances and other reliefs.

Exclude this company. HMRC divides the limits by this number plus one.

365 days in this Corporation Tax period

Usually zero for companies without these distributions. This affects augmented profits for Marginal Relief, not taxable profits. Check the HMRC rules if you are unsure whether a distribution is relevant.

Estimated Corporation Tax

£16,125.00

Marginal Relief · 21.50% effective rate

Profit after Corporation Tax

£58,875.00

Before dividends and other cash movements

Calculation breakdown
Taxable total profits£75,000.00
Adjusted lower limit£50,000.00
Adjusted upper limit£250,000.00
Corporation Tax before Marginal Relief£18,750.00
Marginal Relief− £2,625.00
Estimated Corporation Tax£16,125.00

Important limitations

This estimate does not determine allowable deductions or reliefs and excludes tax credits, R&D relief, instalment-payment rules, ring-fence profits, close investment-holding companies and non-UK resident companies. It is not a Company Tax Return or professional tax advice.

Tips & Guide

Start with taxable total profits

Enter the figure after allowable expenses, capital allowances, trading losses and other deductions have been applied. It can include chargeable gains. Do not enter turnover or ordinary accounting profit unless it already matches the taxable total profits for the Corporation Tax period.

The two headline Corporation Tax rates

For the financial years covered here, the small-profits rate is 19% and the main rate is 25%. The lower and upper profit limits are £50,000 and £250,000 for a 12-month period with no associated companies. A company between the limits may receive Marginal Relief.

Associated companies reduce the limits

The profit limits are divided by the number of associated companies plus the company being calculated. Enter the number of other companies that HMRC treats as associated; ownership, control and accounting-period rules can affect the count, so check the HMRC guidance if you are unsure.

Short accounting periods

If the Corporation Tax accounting period is shorter than 12 months, the £50,000 and £250,000 limits are reduced in proportion to the number of days. The date fields count both the first and last day. Accounts covering more than 12 months must be split into separate Corporation Tax periods.

Estimate a UK limited company’s Corporation Tax from taxable profits. The calculation applies the 19% small-profits rate, the 25% main rate and Marginal Relief, adjusting the profit limits for short accounting periods and associated companies.

How to use the Corporation Tax Liability Calculator (UK)

  1. Enter taxable total profits for one Corporation Tax accounting period, after allowable expenses, losses and reliefs.
  2. Enter the period start and end dates. The dates must describe a period of no more than 12 months, starting on or after 1 April 2023 and ending by 31 March 2027.
  3. Enter the number of other associated companies. Leave it at zero if the company has no associated companies.
  4. If relevant, enter exempt distributions received from companies that are not associated. These affect augmented profits for Marginal Relief, not the taxable-profit figure.
  5. Review the rate band, adjusted profit limits, Marginal Relief and estimated Corporation Tax below.

Examples

£150,000 taxable profit, 12 months, no associated companies

£1,500 Marginal Relief reduces the 25% main-rate amount to an estimated £36,000 Corporation Tax.

£50,000 taxable profit, 12 months, three associated companies

The limits reduce to £12,500 and £62,500, giving an estimated £12,312.50 after Marginal Relief.

How to calculate manually

Marginal Relief

  1. Adjusted upper limit = £250,000 × period fraction ÷ (associated companies + 1)
  2. Augmented profits = taxable profits + relevant exempt distributions
  3. Relief = 3/200 × (adjusted upper limit − augmented profits) × taxable profits ÷ augmented profits
  4. Corporation Tax = taxable profits × 25% − Marginal Relief

The calculator applies the formula only when augmented profits are above the adjusted lower limit and at or below the adjusted upper limit.

The marginal relief fraction of 3/200 reflects the 1.5 percentage-point difference between the 26.5% marginal rate and the 25% main rate.

Frequently asked questions

What profits should I enter in the Corporation Tax calculator?

Enter the company’s taxable total profits for one Corporation Tax accounting period, not turnover or automatically the profit shown in the statutory accounts. Taxable profits are worked out after applying tax rules for allowable expenses, capital allowances, losses, chargeable gains and other reliefs. If your accountant or Company Tax Return working papers already show taxable total profits, use that figure. This estimate does not decide whether a cost or relief is allowable.

How does UK Corporation Tax Marginal Relief work?

For the rates covered by this calculator, profits within the adjusted £50,000 to £250,000 limits may qualify for Marginal Relief. The calculation uses the 3/200 fraction, the adjusted upper limit, augmented profits and taxable profits. Augmented profits can include relevant exempt distributions from companies that are not associated. The relief reduces Corporation Tax otherwise charged at 25%; it does not change the company’s taxable-profit figure.

Why do associated companies change the Corporation Tax thresholds?

HMRC reduces the £50,000 lower limit and £250,000 upper limit by the total number of associated companies, including the company being calculated. For example, three other associated companies mean the limits are divided by four. Whether another company is associated depends on statutory control and related rules, not just whether the companies share a trading name. Check HMRC’s associated-company guidance before relying on the count.

What is included in the Corporation Tax estimate?

The result estimates Corporation Tax on taxable profits under the standard small-profits and main rates, including Marginal Relief where the entered figures qualify. It adjusts the profit limits for the period length and associated-company count. It does not calculate tax credits, R&D relief, instalment payments, ring-fence profits, or special rules for close investment-holding companies or non-UK resident companies. Use the result for planning, not as a filed return or professional tax advice.

Why does the calculator ask for accounting-period dates?

The £50,000 and £250,000 profit limits are reduced for an accounting period shorter than 12 months, so the start and end dates affect the small-profits rate and Marginal Relief calculation. This version supports periods starting on or after 1 April 2023 and ending by 31 March 2027. It counts both dates, rejects periods longer than 12 months, and does not split a long set of accounts into multiple tax periods for you.