HMRC Free CT600 Filing Is Closing March 2026: What Are Your Options?
HMRC's free Corporation Tax filing service closes permanently on 31 March 2026. If you've been using it to file your CT600 returns, you need to find an alternative — and soon.
This guide explains what's happening, why, and what your best options are.
What's Happening?
HMRC has announced that its free online service for filing CT600 Corporation Tax returns will be withdrawn on 31 March 2026. After that date, you will no longer be able to:
- File CT600 returns through HMRC's website
- Use HMRC's free filing tool
- Access the HMRC CT600 filing interface
This affects every UK limited company that currently uses HMRC's free service to file their Corporation Tax returns.
Why Is HMRC Closing the Free Service?
HMRC is modernising its systems and moving towards a model where commercial software providers handle tax filing. This is the same approach used for:
- MTD for VAT — already requires commercial software
- MTD for Income Tax — launching April 2026
- PAYE — already uses commercial software (Basic PAYE Tools or payroll software)
HMRC wants to focus on processing returns and compliance, not building filing software.
How Many Companies Are Affected?
An estimated 200,000-400,000 UK limited companies currently use HMRC's free filing service. These are typically:
- One-director companies with simple affairs
- Dormant companies filing nil returns
- Directors who file their own CT600 without an accountant
- Companies that don't want to pay accountant fees for simple returns
If you're one of them, you need a plan.
Your Options After March 2026
Option 1: Taxpipe — £59 per Filing (Recommended)
Taxpipe is designed specifically as a replacement for HMRC's free filing service:
- Guided wizard — walks you through every CT600 box in plain English
- Auto tax calculation — including marginal relief and financial year splits
- iXBRL accounts included — micro-entity accounts generated automatically
- Direct HMRC submission — files electronically via the Government Gateway
- One-time fee — £59 per return, no subscription
Why it's the closest alternative to HMRC's free service:
- Simple, self-service interface (no accountant needed)
- Designed for directors who file their own returns
- Much cheaper than hiring an accountant
Option 2: Accountant — £300-£800+ per Year
If you prefer someone else to handle your CT600:
- Find a local or online accountant
- They'll prepare and file your CT600 using professional software
- Costs vary widely depending on complexity
Best for: Companies with complex affairs (multiple trades, international income, R&D claims)
Option 3: Other CT600 Software
Several commercial software packages can file CT600 returns:
| Software | Price | Best For |
|---|---|---|
| Taxpipe | £59/filing | DIY directors, simple companies |
| TaxCalc | ~£70/filing | DIY directors |
| GoSimpleTax | ~£58/filing | DIY directors |
| Xero Tax | Needs accountant access | Accountants |
| Sage | From £420/year | Larger companies |
What You Should Do NOW
Before 31 March 2026
- Don't panic — you have time to prepare
- File any outstanding CT600s using HMRC's free service while it's still available
- Choose your replacement software — sign up and familiarise yourself with it
- Test the new process — file your next return through your chosen software
Key Dates
| Date | What Happens |
|---|---|
| Now | Choose replacement software, file outstanding returns |
| 31 March 2026 | HMRC free filing service closes permanently |
| 1 April 2026 | All CT600 filing must use commercial software |
Dormant Companies: You Still Need to File
If your company is dormant (not trading), you still need to file a CT600 every year. The free service closure affects dormant companies too.
The good news: a dormant CT600 is the simplest type — most boxes are zero. Taxpipe's guided wizard detects dormant companies and fast-tracks the process.
Frequently Asked Questions
Will HMRC bring the free service back?
Almost certainly not. HMRC has been gradually shifting to commercial software for years (VAT, PAYE, Income Tax). The CT600 free service is the last one to go.
Can I still file CT600s after March 2026?
Yes — just not through HMRC's free tool. You'll use commercial software (like Taxpipe) that submits to HMRC electronically.
Do I need to change my Government Gateway login?
No. Your Government Gateway credentials stay the same. Commercial software uses the same HMRC system — it just submits your return through the API instead of HMRC's web interface.
Is £59 really the cheapest option?
For a professional, HMRC-compliant CT600 filing with iXBRL accounts, £59 is among the lowest prices available. Compare it to £300+ for an accountant or £70+ for other software.
What if I can't afford filing software?
If cost is a concern, remember that a CT600 is a legal obligation — the penalties for not filing are far more expensive:
- 1 day late: £100 penalty
- 3 months late: another £100
- 6 months late: 10% of unpaid tax
- 12 months late: another 10% of unpaid tax
At £59, Taxpipe is far cheaper than any penalty.
The Bottom Line
The HMRC free filing service was convenient but basic. Its closure is an opportunity to switch to software that's actually better:
- ✅ Guided wizard (HMRC's tool was confusing)
- ✅ Automatic tax calculations (HMRC made you calculate everything yourself)
- ✅ Error checking before submission (HMRC rejected returns without clear explanations)
- ✅ iXBRL accounts included (HMRC's tool didn't generate these)
The transition is straightforward — sign up, enter your figures, and submit. Most directors complete their first Taxpipe filing in under 30 minutes.
Don't wait for the deadline. Sign up for Taxpipe today and be ready before HMRC's free service closes.