Company Tax Return (CT600) vs Annual Accounts: What's the Difference?
CT600 vs annual accounts: one goes to HMRC, one to Companies House. What each is, when they are due, and how they relate.
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Plain-English guides to UK Corporation Tax and CT600 filing.
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How to Appeal a CT600 Late Filing Penalty from HMRC
Got a CT600 late filing penalty? You may be able to appeal. Step-by-step guide to HMRC penalty appeals, reasonable excuses, and time limits.
How to File Your CT600 Yourself in 2026 (Complete DIY Guide)
File your CT600 without an accountant in 2026. What you need, how to prepare accounts, calculate tax, and submit to HMRC.
How Long Does HMRC Take to Process a CT600? Processing Times Explained
Find out how long HMRC takes to process your CT600 company tax return, when you'll get your tax calculation, and what to do if it's taking too long.
HMRC Free CT600 Filing Ends March 2026: Your 5 Best Alternatives
HMRC free CT600 filing ends 31 March 2026. Compare the best alternatives by price, features, and ease of use.
CT600 vs Self Assessment: What's the Difference? (Company vs Personal Tax)
CT600 vs Self Assessment: the key differences between company tax returns and personal tax returns. Who files which and why.
HMRC Enquiry Into Your CT600: What to Expect and How to Respond
Received an HMRC enquiry about your CT600? What triggers enquiries, your rights, what HMRC can ask, and how to respond.
CT600 for Contractors: Filing When You're Inside or Outside IR35
How IR35 status affects your CT600. Practical guide for contractors filing corporation tax — inside IR35, outside IR35, or mixed.
Marginal Relief for Corporation Tax: How It Works (With Calculation Examples)
How marginal relief works for Corporation Tax in 2025/26. Step-by-step calculation for profits between £50,000 and £250,000.
Changing Your Company's Accounting Period: How It Affects Your CT600
What happens to your CT600 when you change your accounting period? Guide to the rules, restrictions, and filing implications.
Company Cars & Corporation Tax: Capital Allowances, BIK, and CT600 Treatment
How company cars affect corporation tax. Capital allowances for cars, benefit in kind rules, and CT600 treatment.
CT600 Supplementary Pages Explained: Which Ones Does Your Company Need?
CT600 supplementary pages explained: CT600A through CT600P. Find out which ones your company needs and how to complete them.