Free CT600 Filing Software: What Are Your Options in 2026?
If you're looking for free CT600 filing software, the landscape is changing fast. HMRC's own free filing service ends on 31 March 2026, and most alternatives cost hundreds of pounds per year.
Here's what's actually available — and what it really costs.
HMRC's Free Filing Service (Ending March 2026)
Until 31 March 2026, HMRC provides a free online tool for filing CT600 returns. It's been the go-to option for small companies filing themselves.
What it offers:
- CT600 form completion
- Basic tax calculation
- Direct submission to HMRC
- Free (taxpayer funded)
What it doesn't offer:
- iXBRL accounts generation (you need to create these separately)
- Tax computations document
- Guided data entry (you need to know which boxes to fill)
- Error checking beyond basic validation
The catch: HMRC is shutting this down on 31 March 2026. After that date, you must use third-party commercial software.
After March 2026: Your Options
Option 1: Accountant Software (Not Free)
Professional accounting software like Xero, FreeAgent, or Sage can file CT600 returns. But they're designed for accountants, not company directors.
| Software | Cost | CT600 Filing? | Notes |
|---|---|---|---|
| Xero | From £15/month (£180/year) | Via add-on only | Need accountant to file |
| FreeAgent | From £19/month (£228/year) | Yes (with limitations) | Best for freelancers |
| Sage | From £12/month (£144/year) | Via accountant | Complex setup |
| QuickBooks | From £12/month (£144/year) | No CT600 filing | Bookkeeping only |
The problem: These are subscription services. You're paying £150-£230 per year even though you only file once a year. And most still require an accountant to actually submit the CT600.
Option 2: Specialist CT600 Software
Dedicated CT600 filing tools are built specifically for company tax returns.
| Software | Cost | iXBRL Included? | Target User |
|---|---|---|---|
| EasyDigitalFiling | From £125/filing | Yes | DIY directors |
| GoSimpleTax | From £58.50/filing | Limited | Self-assessment focus |
| TaxCalc | From £199/year | Yes | Accountants |
| Andica | From £99/year | Yes | Small practices |
| Taxpipe | £59/filing | Yes | DIY directors |
Option 3: Hire an Accountant
Average cost for a small company CT600 filing: £300-£800 per year. This includes:
- Preparing annual accounts
- Filing with Companies House
- Completing and filing the CT600
- Tax planning advice
Worth it if: Your affairs are complex (property, multiple income streams, R&D claims, employees).
Overkill if: You're a simple one-person company with straightforward trading income.
Option 4: DIY with Spreadsheets (Not Recommended)
Technically, you could calculate everything in a spreadsheet and use any HMRC-recognised software just for submission. But:
- You still need to generate iXBRL accounts
- You need to know every CT600 box to fill in
- No validation = high risk of errors
- Errors mean penalties and interest
What "Free" Really Costs
The cheapest approach isn't always the best value. Consider the total cost:
| Approach | Direct Cost | Time | Risk of Errors | Total Real Cost |
|---|---|---|---|---|
| HMRC free tool (pre-April 2026) | £0 | 4-8 hours | Medium-High | £0 + your time |
| Accounting software subscription | £150-£230/year | 2-4 hours | Medium | £150+ ongoing |
| Specialist CT600 software | £59-£199/filing | 1-2 hours | Low | One-off per filing |
| Accountant | £300-£800/year | 0 hours | Very Low | Professional fee |
| DIY spreadsheet + basic software | £0-£50 | 8-16 hours | High | Your time + risk |
Why Most "Free" Options Aren't Really Free
Hidden Costs of Free Tools
- Your time: If it takes 8 hours and your time is worth £30/hour, that's £240
- Error risk: A mistake that triggers an HMRC enquiry costs £500+ in accountant fees to resolve
- Missing iXBRL: HMRC requires iXBRL accounts. Generating these separately can cost £50-£100
- No support: If something goes wrong, you're on your own
The Subscription Trap
Monthly accounting software costs £144-£228 per year, but you only file once. You're paying 11 months of subscription for a once-a-year task.
The Taxpipe Approach
Taxpipe takes a different approach:
- £59 per filing — not per month, not per year
- Everything included: CT600, iXBRL accounts, tax computations, HMRC submission
- Guided process: Answer questions in plain English, we fill in the correct boxes
- Automatic calculations: FY splitting, marginal relief, capital allowances
- No subscription: Pay once when you file, nothing in between
Who Taxpipe Is Built For
- One-person limited companies
- Freelancers and contractors trading through a company
- Small businesses with straightforward affairs
- Directors who previously used HMRC's free tool
- Anyone who doesn't want to pay an accountant £500 for a simple filing
Who Should Use an Accountant Instead
- Companies with complex tax affairs (multiple entities, international income)
- Companies claiming R&D tax credits for the first time
- Companies with property portfolios and multiple income streams
- Companies going through HMRC enquiries
Making the Switch from HMRC Free Filing
If you've been using HMRC's free tool, here's what changes after March 2026:
- Same obligation — you still need to file a CT600
- Same deadline — 12 months after your period end
- Different tool — you'll need commercial software or an accountant
- iXBRL included — most commercial tools (including Taxpipe) generate iXBRL for you, which the HMRC tool didn't
The silver lining: Commercial software actually makes filing easier than HMRC's basic tool. Less manual box-filling, more guidance, better error checking.
Switch to Taxpipe — £59, everything included →
Related Articles
- HMRC Free Filing Is Ending March 2026
- Best CT600 Filing Software UK 2026
- File CT600 Without an Accountant
- Do I Need an Accountant to File My CT600?
- CT600 Filing Checklist
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