HMRC Free CT600 Filing Service Closing March 2026: What You Need to Do
HMRC's free online CT600 filing service will close on 31 March 2026. After this date, all Corporation Tax returns must be filed using commercial software.
What's Changing?
Currently, you can file your CT600 directly through HMRC's online service at no cost. From 1 April 2026:
- ❌ HMRC's free filing portal will no longer accept new returns
- ❌ You won't be able to start a new CT600 on HMRC's system
- ✅ Returns already in progress may be submitted for a short grace period
- ✅ You can still view previously filed returns
Who's Affected?
An estimated 200,000-400,000 company directors who currently use HMRC's free service. This includes:
- Solo directors of limited companies
- Dormant company owners
- Small company directors who file their own returns
- Anyone who doesn't use an accountant or commercial software
What You Need to Do
Before 31 March 2026
- File any outstanding returns through HMRC's free service while you can
- Choose commercial software for future filings
- Save your login details — you'll still need Government Gateway for payment and correspondence
From April 2026 Onwards
- Use commercial software to prepare and file your CT600
- The software will submit electronically to HMRC via their API
- You'll still pay Corporation Tax the same way (bank transfer, direct debit, etc.)
How Much Will It Cost?
Commercial CT600 software ranges from £59 to £200+ per year:
| Option | Cost | Notes |
|---|---|---|
| Taxpipe | £59 per filing | One-off, no subscription |
| TaxCalc | ~£100-200/year | Subscription |
| TaxFiler | ~£80-150/year | Subscription |
| Accountant | £300-1,000+/year | Full service |
Don't Panic — It's Simpler Than You Think
Filing a CT600 with commercial software is actually easier than using HMRC's basic service. Good software will:
- ✅ Calculate your tax automatically (HMRC's service made you do this manually)
- ✅ Generate iXBRL accounts and computations (HMRC's service had limited support)
- ✅ Validate your return before submission (catching errors early)
- ✅ Handle marginal relief and financial year splitting automatically
Timeline
| Date | What Happens |
|---|---|
| Now | HMRC free service still available |
| 31 March 2026 | Free service closes |
| 1 April 2026 | Commercial software required |
| Your deadline | Still 12 months after period end |
Action: Choose Your Software Now
Don't wait until March. Choose your software, create an account, and familiarise yourself with the process. When your next CT600 is due, you'll be ready.
Taxpipe is designed specifically for this transition — company directors who've been using HMRC's free service and need an affordable, simple alternative.
Sign up for Taxpipe — £59 per filing, no subscription. Ready when HMRC's free service closes.