UK Corporation Tax Calculator | CT600 + Marginal Relief

Calculate your UK corporation tax — small profits 19%, main 25%, marginal relief between £50k–£250k. Free, no signup. Updated for 2025-26.

TaxRoot is an HMRC-registered UK tax agent. We file Self Assessment, Corporation Tax, VAT and MTD returns for UK sole traders, landlords and limited companies — entirely online, no office visit needed. Fixed-fee pricing with no hidden charges.

TaxRoot services

• Company Registration — Register your UK Limited Company for just £100
• Self Assessment — File your Self Assessment tax return £134. HMRC-authorised agents handle everything.
• Corporation Tax — Accurate corporation tax filing with real accountants. Stay compliant, stress-free.
• Making Tax Digital — MTD for Income Tax £34/month. Quarterly updates, year-end review, and HMRC filing by authorised agents.
• VAT Returns — MTD-compliant VAT filing handled by UK accountants. From £39/month.

See full pricing · File Self Assessment · Start Corporation Tax filing