The clock is ticking
If you're reading this, you've probably just found out that HMRC's free online CT600 filing tool is closing in March 2026. You need a plan.
Here's the short version: you need commercial software or an accountant to file your Corporation Tax return from April 2026 onwards.
The cheapest and simplest replacement is Taxpipe at £59 per return — no subscription, no hidden fees.
What exactly is changing?
Until now, HMRC let you file a CT600 (Corporation Tax return) for free through their online portal. That portal is being retired.
What's NOT changing:
- You still need to file a CT600 ✅
- The deadline is still 12 months after your accounting period ✅
- The information required is the same ✅
- HMRC still processes returns the same way ✅
What IS changing:
- You can't use HMRC's free tool anymore ❌
- You need to use approved commercial software ✅
- Your software must generate iXBRL accounts ✅
Step-by-step: what to do right now
Step 1: Check your filing deadline
Your CT600 is due 12 months after your accounting period ends. For example:
- Year-end 31 March 2026 → file by 31 March 2027
- Year-end 31 December 2025 → file by 31 December 2026
If your deadline is before March 2026, you can still use HMRC's free tool.
Step 2: Choose your replacement
For most small companies, the decision is simple:
| Option | Cost | Time | Best for |
|---|---|---|---|
| Taxpipe | £59 one-time | 15 minutes | Most small companies |
| Accountant | £300–£1,000/year | Days/weeks | Complex situations |
| Xero/Sage | £15–£50/month | Varies | Companies already using them |
Step 3: File your return
With Taxpipe:
- Sign up (free)
- Enter your company number — we auto-fill your details
- Answer guided questions about your income and expenses
- We calculate your tax and generate all required documents
- Pay £59 and submit directly to HMRC
- Get instant confirmation
That's it. 15 minutes, start to finish.
Frequently asked questions
Can I file a CT600 myself without an accountant?
Yes. If your company is straightforward (single director, UK income, no complex arrangements), software like Taxpipe makes it easy. You don't need accounting qualifications.
What about iXBRL accounts?
HMRC requires accounts in iXBRL format alongside your CT600. Taxpipe generates these automatically — you don't need to worry about it.
Is £59 the total cost?
Yes. No subscription, no monthly fees, no hidden charges. £59 covers your CT600 return, iXBRL micro-entity accounts, and direct HMRC submission. If HMRC rejects your return, we'll fix it and resubmit for free.
What if my company is dormant?
You still need to file a CT600, even if your company hasn't traded. Taxpipe has a dormant company shortcut that pre-fills everything — it takes under 5 minutes.
When should I switch?
Now. Don't wait for the HMRC tool to actually close. Getting familiar with your new software before deadline pressure hits makes everything smoother.
The bottom line
HMRC's free filing tool closing is a minor inconvenience, not a crisis. The replacement software is genuinely better — faster, smarter, and catches errors before you submit.
Try Taxpipe's free calculator to see what your Corporation Tax looks like, then sign up when you're ready to file.