HMRC Free CT600 Filing Service Closed March 2026: What You Need to Do Now
HMRC's free online CT600 filing service closed on 31 March 2026. All Corporation Tax returns must now be filed using commercial software.
What Changed?
Until 31 March 2026, you could file your CT600 directly through HMRC's online service at no cost. From 1 April 2026:
- ❌ HMRC's free filing portal no longer accepts new returns
- ❌ You cannot start a new CT600 on HMRC's system
- ❌ Previously filed returns are no longer viewable online — HMRC advised companies to download at least three years of filed returns before the closure date, as they became unavailable afterwards
- ✅ You can still pay Corporation Tax the same way (bank transfer, direct debit, etc.)
- ✅ You can still contact HMRC about returns and correspondence through your Business Tax Account
Who's Affected?
An estimated 200,000-400,000 company directors who used HMRC's free service. This includes:
- Solo directors of limited companies
- Dormant company owners
- Small company directors who filed their own returns
- Anyone who didn't use an accountant or commercial software
What You Need to Do Now
Since the free service has closed, commercial software is required for any return due from 1 April 2026 onwards. There is no grace period.
If You Haven't Switched Yet
- Choose commercial software immediately — any return due after 31 March 2026 cannot be filed without it
- Keep your Government Gateway details — you'll still need them to authenticate with HMRC through the software
- Retrieve any records you need — if you need copies of old returns, contact HMRC directly, as the free portal is no longer accessible
Going Forward
- Use commercial software to prepare and file your CT600
- The software submits electronically to HMRC via their API
- You'll still pay Corporation Tax the same way (bank transfer, direct debit, etc.)
How Much Does It Cost?
Commercial CT600 options range from £59 per filing (one-off) to £200+ per year (subscription or accountant fees):
| Option | Cost | Notes |
|---|---|---|
| Taxpipe | £59 per filing | One-off, no subscription |
| TaxCalc | ~£100-200/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 calculations automatically — rates for periods straddling 1 April 2023 are worked out for you
Timeline
| Date | What Happened/Happens |
|---|---|
| Before 31 March 2026 | HMRC free service was available |
| 31 March 2026 | Free service closed — no grace period |
| 1 April 2026 | Commercial software required for all new filings |
| Your deadline | Still 12 months after period end |
Act Now: Choose Your Software
If you haven't already switched, choose your software today. Any return due on or after 1 April 2026 must be filed using commercial software — HMRC provided no grace period beyond the 31 March 2026 closure.
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 now that HMRC's free service has closed.