Corporation Tax Calculator
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Company details
Uses verified UK Corporation Tax rules. Supports short and straddling accounting periods. Inputs can be restored during the current browser session. Estimates are not a substitute for company-specific professional advice.
Enter the profit shown in the accounts before Corporation Tax. Ordinary business expenses already included in the accounts should not be entered again.
Enter other associated companies only. This company is included automatically. 0 means one company in total; 1 means two associated companies in total.
Total companies used for the thresholds: 1
Corporation Tax results
Corporation Tax payable
£9,500.00
- Effective Corporation Tax rate
19.0%
- Post-tax profit
£40,500.00
- Accounting period
- 1 April 2026 to 31 March 2027
- Regime applied
- Small-profits rate
Accounting profit
£50,000.00
Taxable profit
£50,000.00
Corporation Tax
£9,500.00
Marginal relief
£0.00
Effective tax rate
19.0%
Post-tax profit
£40,500.00
Profit flow
- Accounting profit £50,000.00
- Tax adjustments to taxable profit £50,000.00
- Corporation Tax £9,500.00
- Post-tax profit £40,500.00
Post-tax profit may be retained or may contribute to future dividend capacity.
See the Director Salary and Dividends guide for how post-tax profit relates to extraction.
Accounting period summary
Company accounting period
1 April 2026 to 31 March 2027
Length
365 days
Applicable financial year
FY2026
Accounting profit versus taxable profit
Accounting profit is the figure shown in the company accounts before Corporation Tax. Taxable profit starts from that figure and applies supported tax adjustments. Ordinary business expenses already included in the accounts should not be entered again. See Corporation Tax Explained for the wider picture.
Small-profits rate, marginal relief and main rate
Where the small-profits and main rates apply, companies with lower augmented profits may pay the small-profits rate, while higher profits pay the main rate. Marginal relief can reduce the charge in between. Associated companies and short periods can change the limits used.
Associated companies
Enter other associated companies only. This company is included automatically, so 0 means one company in total and 1 means two. The calculator displays the total company count and the adjusted limits returned by the engine.
Short accounting periods and periods crossing 1 April
Replace the default dates with your company's actual accounting period. Short periods reduce profit limits on a day basis. Periods that cross 1 April are split across Corporation Tax financial years. Periods longer than 12 months are split into Corporation Tax accounting periods.
Why dividends do not reduce Corporation Tax
Dividends are paid from post-tax profit or reserves. They do not reduce taxable profit. For salary, dividends and extraction modelling, use the Director Salary & Dividend Calculator and the Dividend Tax guide.
Employer pension contributions
Employer pension contributions can reduce taxable profit where they are deductible and not already reflected in accounting profit. Deductibility depends on the facts. Read Employer Pension Contributions and Benefits in Kind for related company costs.
Current limitations
This estimate excludes specialist reliefs such as R&D, Patent Box, creative-industry reliefs, group relief, chargeable gains, property business profits, loss carry-back and quarterly instalment payments. Results are planning estimates, not an HMRC-approved computation.
Frequently asked questions
How is Corporation Tax calculated?
Northline starts from accounting profit, applies supported tax adjustments to estimate taxable profit, then applies Corporation Tax rates and marginal relief for the relevant accounting period and financial year slices.
What is taxable profit?
Taxable profit is the company profit figure after Corporation Tax adjustments such as disallowable expenses, capital allowances, other taxable income and brought-forward losses. It is not automatically the same as accounting profit.
What is marginal relief?
Marginal relief can reduce Corporation Tax when augmented profits sit between the lower and upper profit limits. Associated companies and short accounting periods can reduce those limits.
What are associated companies?
Associated companies are counted with this company when adjusting Corporation Tax profit limits. Enter other associated companies only — this company is included automatically.
What happens if an accounting period crosses 1 April?
Corporation Tax financial years start on 1 April. Where an accounting period straddles that boundary, profits are time-apportioned between the financial years and taxed using the rates and limits that apply to each slice.
What happens if company accounts cover more than 12 months?
A Corporation Tax accounting period cannot exceed 12 months. Where the period of account is longer, Northline splits it into Corporation Tax accounting periods and estimates tax for each part.
Do dividends reduce Corporation Tax?
No. Dividends are an appropriation of post-tax profit. They do not reduce taxable profit for Corporation Tax.
Can employer pension contributions reduce Corporation Tax?
Allowable employer pension contributions can reduce taxable profit where they are not already reflected in accounting profit and are deductible on the facts. This calculator does not independently assess deductibility.
Is post-tax profit the same as distributable reserves?
No. Post-tax profit is an estimate after Corporation Tax. Distributable reserves and available cash depend on company law, prior periods and the company's actual financial position.
Official sources
Figures are estimates and may differ from company accounts, CT600 computations or adviser software. This is not tax, legal or financial advice.
Related guides
- Corporation Tax ExplainedHow UK companies calculate taxable profit, apply Corporation Tax rates and meet filing deadlines.Read guide
- Director Salary and Dividends ExplainedOverview of how owner-directors extract company profit through salary, dividends, pensions and retained profit.Read guide
- Dividend Tax ExplainedHow personal Dividend Tax works — reserves, the dividend allowance, rates and band interaction.Read guide
- Employer Pension Contributions ExplainedHow company-paid pension contributions work for tax, National Insurance, Corporation Tax and annual allowance.Read guide
- Benefits in Kind ExplainedOverview of taxable employer benefits, Class 1A National Insurance, payrolling and P11D.Read guide