HMRC Free CT600 Filing Ended March 2026: Your Options
HMRC's free Corporation Tax Online filing service closed on 31 March 2026. If you were filing your CT600 for free through HMRC's website, you now need to use commercial software or an accountant.
This isn't optional. HMRC no longer accepts CT600 submissions through their website — all filings must go through approved third-party software.
What Changed?
Since 2011, HMRC provided a free online service for filing CT600 corporation tax returns. It was basic but functional, and tens of thousands of directors relied on it each year.
On 31 March 2026, HMRC:
- Closed the Corporation Tax Online filing portal
- Removed the ability to file CT600 returns through their website
- Required all CT600 submissions through third-party software
HMRC's stated reason: the service was outdated and expensive to maintain. They concluded the commercial software market could serve companies more effectively.
Who's Affected?
Every UK company that files a CT600 now needs to use software. Tens of thousands of directors used the free service — if you were among them and haven't yet set up alternative software, you need to act now.
If you already use an accountant or filing software, nothing changes for you.
Your Options After March 2026
Option 1: CT600 Filing Software (Cheapest)
Several software providers offer CT600 filing. Prices range from £59 to several hundred pounds per filing.
| Provider | Price | Notes |
|---|---|---|
| Taxpipe | £59 one-time | Per filing, no subscription |
| TaxCalc | £142 + VAT/year | Annual subscription |
| Andica | £85+/year | Subscription required |
| GoSimpleTax | £90+ | Corporation tax add-on |
| Xero/FreeAgent | Included | But requires full accounting subscription (£20-40/month) |
Taxpipe is the cheapest dedicated CT600 filing option at £59 per return — less than half the price of annual subscription alternatives.
Option 2: Accountant
Hiring an accountant to file your CT600 typically costs:
| Service Level | Typical Cost |
|---|---|
| CT600 filing only | £300-500 |
| Accounts + CT600 | £500-1,000 |
| Full service (bookkeeping + accounts + CT600) | £1,000-3,000/year |
For simple companies (dormant, minimal transactions), an accountant is expensive relative to the work involved. For complex companies, professional advice may be worth the cost.
Option 3: Full Accounting Software
If you already use accounting software like Xero, QuickBooks, or FreeAgent, many of these platforms offer CT600 filing as an add-on or included feature. However:
- You're paying £20-40+/month for the full platform
- CT600 filing may require an upgraded plan
- It's overkill if you only need to file once a year
What Happens If You Don't File?
Late filing penalties apply regardless of how you file — or whether you owe any tax. HMRC doubled the fixed penalties for returns with a filing deadline on or after 1 April 2026:
Filing deadline before 1 April 2026:
| How Late | Penalty |
|---|---|
| 1 day late | £100 |
| 3 months late | Another £100 |
| 6 months late | 10% of unpaid tax (based on HMRC's estimate) |
| 12 months late | Additional 10% of unpaid tax |
Filing deadline on or after 1 April 2026 (new — doubled rates):
| How Late | Penalty |
|---|---|
| 1 day late | £200 |
| 3 months late | Another £200 |
| 6 months late | 10% of unpaid tax |
| 12 months late | Additional 10% of unpaid tax |
For a third consecutive late return, the initial penalty rises to £1,000 under the new regime (£500 under the old). Interest also accrues on any late payment.
What About Dormant Companies?
Dormant companies still need to file at Companies House (dormant accounts), but may not need to file a CT600 if HMRC has been notified the company is dormant.
If your dormant company IS required to file a CT600 (HMRC still expects one), a nil CT600 through software like Taxpipe costs just £59 — cheaper than most accountants charge for a dormant return.
When Should You Switch?
Now, if you haven't already. The HMRC free service closed on 31 March 2026. If you have returns due, you need filing software to submit them.
Most filing software requires minimal setup:
- Create an account
- Enter your company details
- Enter your financial figures
- Submit to HMRC
With Taxpipe, the entire process takes under 30 minutes for a straightforward return.
Frequently Asked Questions
Will HMRC bring back the free service?
No. HMRC has confirmed this is a permanent closure, part of their wider digital strategy to move services to commercial providers.
Can I file a paper CT600?
No. CT600 returns must be filed electronically. Paper filing hasn't been available since 2011.
Was the deadline extended?
No. HMRC did not extend the deadline — the Corporation Tax Online service closed permanently on 31 March 2026.
What if I have returns outstanding from before March 2026?
You can still file late returns through commercial software. The filing format is the same — you just can't use HMRC's portal anymore.
Is Taxpipe HMRC-recognised?
Yes. Taxpipe uses HMRC's official XML submission protocol and has a registered vendor ID (9327). All submissions are validated against HMRC's schema before sending.
Make the Switch Today
Taxpipe was built specifically for directors who've been using HMRC's free service. Our wizard-style interface is designed to be just as simple, with better error checking and instant tax calculations.
£59 per filing. No subscription. No hidden fees.
Start filing → | See how it works →