CT600 Box-by-Box Guide: Every Core Box Explained (2025/26)
Complete walkthrough of every CT600 box from 1 to 620. Plain English explanations, what to enter, and which boxes most small companies actually use.
Plain-English guides to UK Corporation Tax and CT600 filing.
Complete walkthrough of every CT600 box from 1 to 620. Plain English explanations, what to enter, and which boxes most small companies actually use.
Find out if your dormant company must file a CT600 with HMRC. When you're exempt, when you must file, and how to submit a nil return.
How dividends interact with Corporation Tax — paying dividends, receiving dividends, the dividend exemption, franked investment income, and CT600 reporting for UK companies.
All corporation tax deadlines for 2026 — CT600 filing dates, payment due dates, and penalties for late filing. Key dates for UK limited companies.
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.
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.
How is bank interest taxed for UK limited companies? Learn the CT600 treatment, reporting requirements, and how to reduce your corporation tax on savings interest.
How UK companies pay corporation tax on overseas income. Covers foreign trading profits, dividends, rental income, double taxation relief, and CT600 reporting.
Reduce your corporation tax bill before year end. 12 practical planning tips for UK limited companies — from pension contributions to capital allowances and loss relief.
How UK small and medium-sized companies can claim R&D tax credits. Covers eligibility, qualifying costs, calculation examples, the merged scheme, and how to include R&D relief on your CT600.
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.