Corporation tax is paid on your company's profits. The rate depends on how much you earn.

Rates (2026)

  • Profits under £50,000: 19% (small profits rate)
  • Profits £50,000–£250,000: Marginal relief applies (effective rate between 19-25%)
  • Profits over £250,000: 25% (main rate)

Deadlines

  • CT600 return: File within 12 months of accounting period end
  • Payment: Due 9 months and 1 day after accounting period end
  • Late filing penalty: £100 (escalating to £1,600+)
  • Late payment: Interest from day one

Legitimate Deductions

You can deduct: office rent, virtual office fees, equipment, travel, salaries, pension contributions, and professional subscriptions. Keep records for 6 years.

See our compliance checklist for all filing obligations.