UK Corporation Tax & Marginal Relief Calculator (2026)
Calculate your CT600 liability across the 19% Small Profits Rate, 25% Main Rate, and exact Marginal Relief bracket.
£120,000
£50k (19% Rate)£150k (Marginal Relief)£250k+ (25% Rate)
Adjusts lower threshold to £50,000 & upper threshold to £250,000.
Corporation Tax Breakdown
Gross Taxable Profit:£120,000
Full Tax at 25%:£30,000
Marginal Relief Discount (3/200):-£1,950
Effective Tax Rate:23.38%
Net Corporation Tax Due (CT600)
£28,050
Retained Profit After CT:£91,950