What Is Happening?
For years, HMRC offered a free online tool that allowed UK limited companies to file their CT600 Corporation Tax returns directly. This tool — accessible through the HMRC Government Gateway — was the go-to option for micro-entity companies and sole directors filing without an accountant.
That tool is closing in March 2026. After the shutdown, you will no longer be able to file your Corporation Tax return through HMRC's own portal. Instead, you'll need to use approved third-party software or pay an accountant to file on your behalf.
Why Is HMRC Ending Free Filing?
The closure is part of HMRC's broader push towards Making Tax Digital (MTD). HMRC's legacy systems are expensive to maintain and don't support the digital record-keeping requirements that MTD will eventually mandate for Corporation Tax.
By transitioning to commercial software, HMRC expects better data quality, fewer errors in returns, and reduced support costs. The trade-off is that companies must now pay for filing software or accountancy services.
Who Is Affected?
This change primarily affects small and micro-entity companies that currently file their own CT600 returns through HMRC's free tool. If you already use an accountant or commercial software, you won't notice any difference.
The companies hit hardest are those with simple affairs — sole directors, dormant companies, or businesses with straightforward trading that previously managed tax filing themselves at zero cost.
What Are Your Options?
After March 2026, you have three main alternatives:
1. Hire an Accountant
The traditional route. Accountants typically charge £300–£1,000+ per year for CT600 filing and company accounts. This makes sense for complex businesses, but is overkill for simple micro-entity companies.
2. Use Established Tax Software
Products like TaxCalc, Xero, and FreeAgent offer CT600 filing capabilities. However, they tend to be designed for accountants, can be complex, and often require annual subscriptions starting from £150–£400 per year.
3. Use Taxpipe — Purpose-Built for Self-Filers
Taxpipe is built specifically for the directors who are losing access to HMRC's free tool. At just £59 per CT600 return, it's the most affordable commercial option available.
Why Taxpipe Is the Best Alternative
Unlike accountant-focused software, Taxpipe is designed for company directors with no accounting background:
- Guided wizard — plain-English questions walk you through your return step by step
- Automatic computation — Corporation Tax, capital allowances, and all CT600 boxes calculated for you
- Micro-entity accounts — iXBRL-tagged accounts generated and filed with Companies House
- Direct HMRC submission — one-click filing with instant confirmation receipt
- Pay per return — no monthly subscription, no lock-in. £59 when you need it
Not sure how much Corporation Tax you owe? Try our free Corporation Tax calculator to get an instant estimate.
What You Should Do Now
- Check your filing deadline — your CT600 is due 12 months after your company's accounting period ends. See our guide on CT600 deadlines.
- Gather your records — bank statements, invoices, and expenses for the period. Here's what you need.
- Sign up for Taxpipe — create your account now so you're ready when HMRC's tool closes.
- Don't miss the deadline — late filing penalties start at £100 and escalate quickly.
Frequently Asked Questions
When is HMRC closing its free CT600 filing tool?
HMRC has announced that its free online CT600 filing service will close in March 2026. After this date, companies will no longer be able to submit Corporation Tax returns directly through HMRC's own portal.
Why is HMRC ending free CT600 filing?
HMRC is moving towards a Making Tax Digital (MTD) framework and consolidating its services. The free filing tool was built on legacy technology that is expensive to maintain, and HMRC is encouraging the use of third-party commercial software instead.
What happens if I don't switch before March 2026?
You will not be able to file your CT600 return through HMRC's portal. You'll need to use approved third-party software or hire an accountant. Missing your filing deadline results in automatic penalties starting at £100, rising to £1,600 or more for extended delays.
What is the cheapest alternative to HMRC free filing?
Taxpipe offers CT600 filing for just £59 per return — the most affordable option on the market. This includes guided data entry, automatic tax computation, iXBRL micro-entity accounts, and direct HMRC submission.
Do I need an accountant to file my CT600?
No. If your company is a micro-entity (turnover under £632,000, balance sheet under £316,000, fewer than 10 employees), you can file your CT600 yourself using software like Taxpipe. Our guided wizard asks plain-English questions — no accounting knowledge required.
Can Taxpipe submit my CT600 directly to HMRC?
Yes. Taxpipe is authorised to submit CT600 returns and micro-entity accounts directly to HMRC via their Government Gateway API. You get a confirmation receipt immediately after submission.