Small Company Corporation Tax Rates 2025/2026: Complete Guide
Understand corporation tax rates for small companies in 2025/2026, including the 19% and 25% thresholds, marginal relief calculation, and associated companies rules.
Plain-English guides to UK Corporation Tax and CT600 filing.
Understand corporation tax rates for small companies in 2025/2026, including the 19% and 25% thresholds, marginal relief calculation, and associated companies rules.
New limited company? Learn when to register for corporation tax, your first accounting period, filing deadlines, and how to avoid common first-year mistakes.
Understand how a director's loan account affects your corporation tax, including the S455 charge at 33.75%, repayment rules, and CT600 reporting.
Overpaid corporation tax? Learn how to claim a refund from HMRC, amend your CT600, and understand timelines for getting your money back.
Learn how and when to file a CT600 nil return for a dormant or non-trading company, including deadlines, penalties, and step-by-step guidance.
Step-by-step guide to setting up and using your HMRC Government Gateway account to file your CT600 Corporation Tax Return online.
HMRC's free CT600 online filing service closed on 31 March 2026. Compare what it offered against commercial software, and see what your filing options are now.
How goodwill and intangible assets are treated for Corporation Tax. Covers the acquisition date rules, writing-down allowances, rollover relief, and CT600 reporting.
Is employer NIC an allowable deduction for corporation tax? Yes. Learn how employer National Insurance works, current rates, the Employment Allowance, and how to claim on your CT600.
How does corporation tax work for investment companies? Guide to holding investments through a limited company — dividends, capital gains, property, and filing your CT600.
Complete history of UK corporation tax rates from 1965 to 2026. See how rates have changed, key reforms, and what current rates mean for your limited company.
Owe money to your company? Learn how an overdrawn director's loan account triggers S455 tax on your CT600, how much you'll pay, and how to get it back.