Corporation Tax Calculator 2026/27

Corporation Tax Calculator

✓ Verified for 2026/27

Your Details

£
Corporation Tax Due
£19,000
Small Profits Rate
Effective Rate
19.0%
of taxable profit
Post-Tax Profit
£81,000
retained in company
Monthly Equivalent
£6,750
post-tax ÷ 12

Tax Breakdown

Annual Profit £100,000
Corporation Tax £19,000
Post-Tax Profit £81,000
Post-Tax Profit 81%
Corp Tax 19%
Threshold Rate Applies?
Up to £50,000 19% Small Profits –
£50,001–£250,000 Marginal Relief –
Over £250,000 25% Main Rate –
ℹ️ If you have associated companies, the thresholds are divided equally. E.g. 2 associated companies → thresholds are £16,667 and £83,333.

How We Calculated This

  1. Determine Net Profit: Calculate the company's taxable profits (revenue minus tax-deductible expenses).
  2. Identify Associated Companies: Divide the tax thresholds (£50,000 and £250,000) equally by the number of associated companies.
  3. Apply Small Profits Rate: Apply 19% Corporation Tax if profits are below the lower limit.
  4. Apply Main Rate: Apply 25% Corporation Tax if profits are above the upper limit.
  5. Apply Marginal Relief: If profit is between the thresholds, apply a sliding-scale formula to determine the blended rate.

Real-World Examples

Example 1: Company Profit of £40,000

Small business with profits under the £50,000 threshold (no associated companies).

Taxable Profit: £40,000
Corporation Tax Rate: 19%

Tax Due: £40,000 * 19% = £7,600
Retained Earnings: £32,400
Example 2: Company Profit of £150,000 (Marginal Relief)

Profit falls between the £50,000 and £250,000 thresholds, qualifying for Marginal Relief.

Taxable Profit: £150,000
Tax at 25% Main Rate: £37,500

Marginal Relief Calculation:
(£250,000 - £150,000) * (3/200) = £1,500

Net Corporation Tax: £37,500 - £1,500 = £36,000
Effective Tax Rate: 24%

Frequently Asked Questions

What is the Corporation Tax rate for 2026/27?

The main rate is 25% on profits over £250,000. The small profits rate is 19% on profits up to £50,000. Marginal relief applies between these thresholds.

What is marginal relief?

Marginal relief reduces your effective tax rate when profits fall between £50,000 and £250,000, producing a blended rate between 19% and 25%.

Are there associated company rules?

If you have associated companies, the thresholds are divided equally between them. This can significantly increase your effective tax rate.

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Frequently Asked Questions

What is the Corporation Tax rate for 2026/27?

The main rate is 25% on profits over £250,000. The small profits rate is 19% on profits up to £50,000. Marginal relief applies between these thresholds.

What is marginal relief?

Marginal relief reduces your effective tax rate when profits fall between £50,000 and £250,000, producing a blended rate between 19% and 25%.

Are there associated company rules?

If you have associated companies, the thresholds are divided equally between them. This can significantly increase your effective tax rate.