Calculate Company Corporation Tax
How Does UK Corporation Tax Work in 2026/27?
UK Corporation Tax is charged on taxable trading profits, capital gains, and investment income earned by UK limited companies. For the 2026/27 financial year, the statutory system operates two headline tax rates connected by a sliding scale of Marginal Relief.
What are the Official UK Corporation Tax Bands and Rates for 2026/27?
Companies with profits below £50,000 pay the 19% Small Profits Rate, while profits exceeding £250,000 incur the 25% Main Rate. Profits between £50,000 and £250,000 benefit from statutory Marginal Relief.
| Taxable Profit Threshold | Effective Rate Range | Statutory Classification |
|---|---|---|
| Up to £50,000 | 19% | Small Profits Rate |
| £50,001 to £250,000 | 19% – 25% | Marginal Relief (Standard Fraction: 3/200) |
| Over £250,000 | 25% | Main Rate |
How is Marginal Relief Calculated on Profits Between £50,000 and £250,000?
Marginal Relief bridges the tax gap between 19% and 25%, ensuring businesses do not face an abrupt tax cliff edge. Tax is computed at the 25% main rate and reduced by applying the statutory 3/200 relief fraction.
The statutory HMRC Marginal Relief formula is:
Corporation Tax Due = (Taxable Profit × 25%) − Marginal Relief
Step-by-Step Corporation Tax Calculations (Worked Examples)
The worked mathematical examples below demonstrate exact tax calculations across small, mid-tier marginal relief, and high-profit scenarios.
£40,000 Profit (Small Business)
£100,000 Profit (Marginal Relief Math)
£300,000 Profit (Main Rate)
Frequently Asked Questions
What is the UK Corporation Tax rate for 2026/27?
The UK Corporation Tax main rate is 25% for profits over £250,000, and the small profits rate is 19% for profits up to £50,000. Marginal relief applies between £50,000 and £250,000.
How is Corporation Tax Marginal Relief calculated?
Marginal relief reduces the 25% main rate using the formula: (£250,000 − Taxable Profit) × (3/200). The resulting relief amount is deducted from the 25% tax calculation.
What is the Marginal Relief fraction for 2026/27?
The statutory standard Marginal Relief fraction is 3/200 (or 0.015). This provides a gradual taper from 19% to 25% as company profits increase.
How do associated companies affect Corporation Tax thresholds?
The £50,000 lower and £250,000 upper thresholds are divided equally by the total number of associated companies plus one, accelerating the point where higher tax rates apply.