How to File a CT600 for a Dormant Company (Step-by-Step)
Complete guide to filing a dormant company CT600. Even if your company did nothing, you still need to file. Here's exactly how.
Blog
Plain-English guides to UK Corporation Tax and CT600 filing.
182 results for “CT600”Clear search
What Happens If You Miss Your CT600 Filing Deadline?
Late CT600 filing penalties explained: from 1 April 2026, £200 on day one and £400 at 3 months — doubled from previous rates. Plus 10% tax-geared penalties and 7.75% late payment interest. How to minimise the damage.
HMRC Free CT600 Filing Is Ending March 2026 — What You Need to Do Now
HMRC is closing its free Corporation Tax filing service on 31 March 2026. Here's what this means for your company and the cheapest alternatives.
What Is iXBRL and Why Does Your CT600 Need It?
Plain English explanation of iXBRL — the tagged format HMRC requires for CT600 accounts and tax computations. What it is, why it matters, and how to create it.
HMRC Free Filing Software Is Closing March 2026 — What Now?
HMRC is shutting down its free CT600 filing service on 31 March 2026. Here's what it means for your company and the cheapest alternatives.
10 CT600 Mistakes That Get Your Return Rejected by HMRC
The most common CT600 filing mistakes that cause HMRC rejections. Learn what to avoid so your Corporation Tax return gets accepted first time.
R&D Tax Credits for Small Companies: Save Up to 27% on Innovation Costs
How SME R&D tax relief works for small companies. Qualifying activities, how to calculate the benefit, and reporting on your CT600.
Corporation Tax for Landlords: Running a Property Company in 2025/26
Complete guide to Corporation Tax for property investment companies. Buy-to-let through a limited company, allowable expenses, mortgage interest relief, and CT600 filing.
IR35 & Off-Payroll Rules: How They Affect Your Corporation Tax
How IR35 and off-payroll working rules impact your limited company CT600. Inside vs outside IR35, deemed payments, and tax implications explained.
Changing Your Company Year End: CT600 & Tax Implications
How changing your accounting reference date affects your CT600 filing. Short periods, long periods split into two returns, and tax planning opportunities.
HMRC Free CT600 Filing Service Closed March 2026: What You Need to Do Now
HMRC closed its free Corporation Tax filing service on 31 March 2026. What this means for your company and how to file now.
Best CT600 Filing Software UK 2026: Complete Comparison Guide
Comprehensive comparison of all CT600 filing software options in the UK for 2026. Features, pricing, pros and cons of every HMRC-recognised option.