CT600 Box-by-Box Guide: Which Boxes Do You Actually Need to Fill In?
A plain English guide to the CT600 boxes that matter for small companies. Learn which boxes to fill in, which to skip, and how to avoid common mistakes.
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Plain-English guides to UK Corporation Tax and CT600 filing.
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CT600 Filing for First-Time Directors: Complete Beginner's Guide
Never filed a CT600 before? This step-by-step guide explains everything first-time directors need to know — deadlines, documents, iXBRL, and how to file for £59.
How to File CT600 Online in 2026: Complete Step-by-Step Guide
HMRC's free filing service closed on 31 March 2026. Here's exactly how to file your CT600 corporation tax return online in 2026 — step by step, with tips and common mistakes to avoid.
CT600 Supplementary Pages: Which Ones Does Your Company Need?
Not sure which CT600 supplementary pages to file? This guide explains each page — CT600A to CT600J — and tells you exactly which ones your company needs.
Full Expensing: 100% Capital Allowances Made Permanent (2025 Guide)
Full expensing lets your company deduct 100% of qualifying plant and machinery costs immediately. Here's who qualifies, what's included, and how to claim on your CT600.
UK Corporation Tax Rates 2025/26: Complete Guide with Examples
Corporation tax rates for 2025/26: 19% small profits rate, 25% main rate, and marginal relief in between. Includes worked examples and thresholds.
What Is iXBRL? Inline XBRL Explained Simply for Company Directors
HMRC requires iXBRL for CT600 accounts and tax computations. What is it, why does it matter, and how do you create it? Plain English guide for directors.
How to Get a Corporation Tax Refund from HMRC (Overpayment Guide)
Overpaid corporation tax? Learn how to claim a refund from HMRC, how long it takes, and what to do if your refund is delayed.
Filing Annual Accounts at Companies House: Complete Guide for Limited Companies
Everything you need to know about filing your company's annual accounts at Companies House — deadlines, formats, micro-entity vs small company, and penalties.
First Year Corporation Tax: What New Limited Companies Need to Know
Just incorporated? Here's your complete guide to corporation tax in your first year — registration, deadlines, what to file, and how to pay.
How to Pay Corporation Tax: Complete HMRC Payment Guide 2025/26
Step-by-step guide to paying your corporation tax bill. Covers all payment methods, deadlines, payment references, and what happens if you pay late.
HMRC Free Filing Has Closed: What to Use Instead
HMRC's free CT600 filing service closed on 31 March 2026. Step-by-step guide to choosing a replacement and filing your Corporation Tax return.