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.
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Plain-English guides to UK Corporation Tax and CT600 filing.
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Company Director Tax Responsibilities: What You Must Do (and When)
Every UK company director has legal tax obligations. This checklist covers corporation tax, PAYE, VAT, confirmation statements, and key deadlines.
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.
HMRC Free CT600 Filing Ended March 2026: What Are Your Options?
HMRC's free Corporation Tax Online service closed 31 March 2026. Here's what changed and the cheapest ways to file your CT600 now that the free option is gone.
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.
What Happens After You File Your CT600? HMRC Processing Timeline
Filed your CT600? Here's what happens next — HMRC processing times, status updates, potential enquiries, and when to expect confirmation.
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.
How to Amend a CT600 Tax Return: Correcting Mistakes After Filing
Made an error on your CT600? Learn how to amend your corporation tax return within the 12-month deadline, what changes HMRC allows, and the step-by-step process.
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.
Best Alternatives to HMRC's Free Filing Service in 2026
HMRC's free CT600 filing tool closes March 2026. Compare the best alternatives: Taxpipe (£59), accountants, and full accounting software for UK limited companies.
Dormant Company Corporation Tax: Do You Need to File a CT600?
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.