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.
Blog
Plain-English guides to UK Corporation Tax and CT600 filing.
184 results for “ct600”Clear search
Do I Need to File a CT600? When Your Company Must Submit a Tax Return
Find out whether your limited company needs to file a CT600 Corporation Tax return with HMRC. Covers dormant companies, new companies, losses, and exemptions.
Corporation Tax for Startups: The Complete Guide for New Limited Companies
Corporation tax for startups. Registration, deadlines, expenses, R&D relief, first CT600 filing, and mistakes to avoid.
Every Corporation Tax Relief Available to UK Companies (2025/26 Complete List)
Every corporation tax relief for UK companies in 2025/26 — R&D, creative industry, patent box, capital allowances, and more.
Free CT600 Filing Software: What Are Your Options in 2026?
Free CT600 filing software compared. HMRC's free filing service closed in March 2026 — here's what it offered and what to use instead.
Corporation Tax Interest: Late Payment Rates, Repayment Interest & How to Avoid Charges
HMRC charges interest on late corporation tax at base rate + 4% — currently 7.75%. Learn current rates, how interest is calculated, and how to avoid it.
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 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.
Making Tax Digital for Corporation Tax: What Your Company Needs to Know
HMRC cancelled Making Tax Digital for Corporation Tax in July 2025. Here's what happened, what it means for your company, and what filing changes do affect you now.
Just Incorporated? Your First CT600 Timeline: Key Dates You Can't Miss
New limited company timeline: when to register for corporation tax, your first accounting period, CT600 deadline, and payment date.
Non-UK Company Trading in the UK? When You Need to Pay Corporation Tax
Non-UK company with UK activities? When you must register for corporation tax, file a CT600, and what counts as a permanent establishment.
Corporation Tax on Cryptocurrency: How to Report Bitcoin & Crypto on Your CT600
How UK companies pay corporation tax on crypto. Buying, selling, mining, staking, DeFi, and NFTs — what goes on your CT600.