Company Year End: 31 March vs Other Dates — How It Affects Your CT600
Does your company year end matter for corporation tax? Yes. Here's how 31 March simplifies your CT600 filing, and what happens with other year-end dates.
Plain-English guides to UK Corporation Tax and CT600 filing.
Does your company year end matter for corporation tax? Yes. Here's how 31 March simplifies your CT600 filing, and what happens with other year-end dates.
The CT600 has over 200 boxes but most companies only use a fraction. Here are the key boxes you need to know, what goes in each one, and common mistakes to avoid.
The CT600 has 200+ boxes but most companies only need about 30. Here's exactly which boxes matter for your company type — micro-entity, small, or dormant.
Complete guide to claiming capital allowances on your CT600. Covers Annual Investment Allowance (AIA), full expensing, writing down allowances, and which boxes to fill in.
How to claim capital allowances on your CT600 for equipment, vehicles, and machinery. Covers AIA, writing down allowances, full expensing, and which CT600 boxes to use.
HMRC charges escalating penalties for late CT600 filing, starting at £100. Here's exactly what happens, how to avoid penalties, and what to do if you've already missed the deadline.
Marginal relief reduces corporation tax for companies with profits between £50,000 and £250,000. Learn how it works, how to calculate it, and how it appears on your CT600.
Your dormant company still needs to file a CT600 with HMRC. Here's how to file a nil return quickly and avoid penalties — even if your company did nothing all year.
New company director? This beginner-friendly guide explains CT600 corporation tax returns: what they are, when to file, what you need, and how to do it yourself.
Step-by-step guide to filing your CT600 corporation tax return online using commercial software after HMRC discontinues its free filing service in March 2026.
Plain English explanation of every CT600 box that matters for a typical small limited company. No jargon, no confusion.
Complete guide to filing a dormant company CT600. Even if your company did nothing, you still need to file. Here's exactly how.