HMRC Free CT600 Filing Ends March 2026: Your Options
HMRC's free Corporation Tax Online filing service will close on 31 March 2026. If you've been filing your CT600 for free through HMRC's website, you need a plan.
This isn't optional. After March 2026, you MUST use commercial software or an accountant.
What's Changing?
Since 2011, HMRC has provided a free online service for filing CT600 corporation tax returns. It's basic but functional, and hundreds of thousands of directors use it every year.
On 31 March 2026, HMRC will:
- Close the Corporation Tax Online filing portal
- Remove the ability to file CT600 returns through their website
- Require all CT600 submissions through third-party software
HMRC's stated reason: the service is outdated and expensive to maintain. They believe the commercial software market can serve companies more effectively.
Who's Affected?
Every UK company that files a CT600 must now use software. HMRC estimates this affects 200,000-400,000 companies who currently use the free service.
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 | £136.80/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?
The same penalties apply regardless of how you file:
| How Late | Penalty |
|---|---|
| 1 day late | £100 |
| 3 months late | Another £100 |
| 6 months late | 10% of unpaid tax |
| 12 months late | Additional 10% of unpaid tax |
| 3+ years late | HMRC estimates your tax bill |
Plus interest on any late payment. Late filing penalties apply even if you owe no tax.
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. Don't wait until 31 March 2026. The free service could become unreliable as HMRC winds it down, and you don't want to be scrambling for software on deadline day.
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.
Will the deadline be extended?
Unlikely. HMRC has been telegraphing this change since 2024.
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 →