If you've been using HMRC's free online service to file your company's CT600 Corporation Tax return, there's an important change coming. HMRC is retiring its free filing tool, and after March 2026 you'll need to use commercial software instead.
Here's what's happening, who it affects, and what you can do about it.
What's changing?
HMRC has offered a basic free tool for filing CT600 returns for several years. It was never fancy — the interface felt like it was designed in the early 2000s — but it worked, and it was free.
Now HMRC is discontinuing that service. From March 2026, the free filing tool will no longer be available. If you try to use it, you'll be redirected to a page telling you to use commercial software.
This isn't just a rumour or speculation. HMRC has published guidance confirming the change and has been sending notices to companies that previously used the free service.
Why is HMRC doing this?
HMRC hasn't given a single clear reason, but reading between the lines it comes down to a few factors:
- Maintenance costs — keeping legacy software running is expensive, especially when it handles sensitive tax data
- Limited functionality — the free tool only supported simple returns and couldn't handle things like group relief, R&D claims, or multiple accounting periods
- Commercial market — there's now a healthy market of software providers offering CT600 filing, so HMRC may feel the free tool is no longer needed
- Making Tax Digital — HMRC's broader push towards digital tax administration likely means consolidating onto fewer, more modern platforms
Whatever the reason, the result is the same: if you relied on the free tool, you need a new plan.
Who does this affect?
This affects any company director or small business owner who was filing their CT600 directly through HMRC's website without using third-party software. That's a significant number of people — estimates suggest tens of thousands of small companies used the free service each year.
If you've always used an accountant, or if you already use commercial filing software, this change doesn't directly affect you. Your accountant or software provider will continue filing on your behalf as normal.
The people most affected are:
- Solo directors of small limited companies (freelancers, contractors, consultants)
- Dormant company owners who filed simple nil returns through the free tool
- Cost-conscious business owners who chose the free option to avoid paying an accountant or software fees
What are your options now?
You have three main choices:
1. Use commercial CT600 software
This is the most straightforward replacement. There are several options on the market at different price points. Some are designed for accountants and can be overwhelming for someone who isn't a tax professional. Others, like Taxpipe, are built specifically for company directors who want to file themselves.
When choosing software, look for:
- Plain English guidance — not just empty boxes expecting you to know what goes where
- iXBRL accounts included — some tools charge extra for generating the accounts you need to submit alongside your CT600
- HMRC integration — the ability to submit directly to HMRC without exporting and uploading files separately
- Fair pricing — you shouldn't need to pay hundreds of pounds for a simple return
2. Hire an accountant
If you'd rather not deal with it yourself, an accountant can file your CT600 for you. For a straightforward small company, expect to pay somewhere between £300 and £800 per year, depending on your location and the accountant's rates.
This is a perfectly valid option, but it's worth knowing that for a simple company — say, one director, no employees, straightforward income and expenses — the CT600 itself isn't complicated. Much of what you'd be paying an accountant for is the software and the time to enter the numbers you already know.
3. Close your dormant company
If you have a dormant company that you're not planning to use, this might be a good time to close it down. Filing a CT600 each year for a company that does nothing is an overhead you can eliminate entirely.
You can strike off a dormant company through Companies House for a small fee (currently £33 online). Just make sure you file any outstanding returns first, or HMRC may object to the strike-off.
What happens if you don't file?
Nothing changes here — the penalties for late filing remain the same regardless of which tool you use (or don't use). If you miss your CT600 deadline:
- 1 day late — £100 penalty
- 3 months late — another £100 penalty
- 6 months late — HMRC estimates your tax bill and adds 10% of that as a penalty
- 12 months late — another 10% penalty on top
These add up fast, especially combined with interest on any unpaid tax. And because HMRC can estimate your tax bill for the penalty calculation, the amount can be surprisingly high even if you didn't actually owe much.
How to prepare
The transition doesn't need to be stressful. Here's a simple checklist:
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Check your filing deadline — find out when your next CT600 is due. If it's before March 2026, you may still be able to use the free tool one last time.
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Gather your records — get your income, expenses, and bank statements organised for your accounting period. Having these ready makes the actual filing much quicker.
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Choose your filing method — decide whether you'll use software or an accountant. If software, sign up and get familiar with it before your deadline.
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Don't leave it to the last minute — the worst time to figure out new software is the day before your filing deadline.
The silver lining
Here's the thing: the free HMRC tool wasn't actually that good. It offered no guidance, no error checking, and no way to save your progress. Many people who used it spent hours wrestling with it, unsure whether they were filling in the right boxes.
Modern filing software is genuinely better. It asks you questions in plain English, does the calculations for you, validates your return before submission, and keeps a copy for your records. For many people, switching to a proper tool will actually make the process easier, not harder.
At Taxpipe, we've priced our service at £59 per return — which is a fraction of what an accountant charges and includes everything you need: the CT600 form, micro-entity accounts in iXBRL format, and direct submission to HMRC. We built it specifically for company directors who want to file themselves without needing to learn accounting jargon.
Key dates to remember
- March 2026 — HMRC free filing tool closes
- Your company's accounting period end date + 9 months — Corporation Tax payment deadline
- Your company's accounting period end date + 12 months — CT600 filing deadline
If you're unsure when your deadlines are, you can check on your HMRC online account or on your company's entry at Companies House.
The end of HMRC's free filing service is a change, but it doesn't have to be a problem. With a few minutes of preparation, you can find a filing method that works for you — and might even save you time compared to the old tool.
Switch to Taxpipe
Taxpipe is the simple, affordable replacement for HMRC's free filing tool. Same direct HMRC submission, but with a better interface, auto-computation, and iXBRL accounts included. £59 per filing.
Related articles
- How to File a CT600 Online — Step by Step
- Corporation Tax Allowable Expenses — Complete List
- Your First Company Tax Return
- Filing a CT600 for a Dormant Company
- Free CT600 Filing Software: Your Options in 2026