Corporation Tax Calculator
Estimate your UK limited company's Corporation Tax liability, including marginal relief where augmented profits fall between the lower and upper limits. Results split across financial years automatically.
Period & profit
Corporation Tax due
£0.00
Period 01/04/2025 – 31/03/2026
Marginal relief
£0.00
No relief applies
Effective rate
0.00%
−25.00pp vs main rate
Period breakdown
| Period | Profit | Rate | Tax | Marginal relief | Net tax |
|---|---|---|---|---|---|
| Total | 0.00 | — | 0.00 | 0.00 | 0.00 |
Marginal relief workings
Marginal relief applies where augmented profits fall between the lower and upper limits:
(
Upper limit
−
Augmented profits
)
×
(
Taxable profits
÷
Augmented profits
)
×
Marginal relief fraction
Apportionment basis
Days in the financial year
365
Days in this accounting period
365
Associated companies
Including this company
1
Marginal relief limits (£)
Lower limit
50,000 × 365 ÷ 365
50,000.00
Upper limit
250,000 × 365 ÷ 365
250,000.00
Profits (£)
Taxable profits
0.00
Augmented profits
Taxable + non-group dividends received
0.00
Relief calculation (£)
Upper limit
250,000.00
Less: augmented profits
(0.00)
Margin below the upper limit
250,000.00
Proportion chargeable
Taxable ÷ augmented profits
0.0000
Marginal relief fraction
3/200 (FY 2025)
0.0150
Marginal relief for FY 2025
£0.00
Estimate only. Figures are based on HMRC's published rates
and assume a single trading entity with no group surrender, no R&D credits
and no chargeable gains. For a binding calculation, run a full CT600 in
your dashboard.