Looking for an alternative to HMRC’s Company Accounts and Tax Online service?
HMRC’s free service for filing company accounts and Company Tax Returns closed on 31 March 2026. A4O Accounts prepares your accounts and CT600 from your books and files them with Companies House and HMRC.
Free to get started, including filing. No card required.
What happened. HMRC’s “File your accounts and Company Tax Return” online service, often called CATO, closed on 31 March 2026. From 1 April 2026, annual accounts and Company Tax Returns go to HMRC through commercial software. Your accounts still go to Companies House as well.
Source: GOV.UK — Filing company accounts and tax returns if you previously used the HMRC online service. Last checked 1 October 2026.
What changed, and what didn’t
| Before 31 March 2026 | Now | |
|---|---|---|
| Company Tax Return to HMRC | HMRC’s free online service, or commercial software | Commercial software |
| Accounts to Companies House | Companies House’s own service, software or paper | The same, until accounts move to software-only filing in April 2028 |
| Return deadline | 12 months after the accounting period ends | Unchanged |
| Corporation Tax payment | Usually 9 months and 1 day after the period ends | Unchanged |
More on the dates in Corporation Tax deadlines and the April 2028 change at Companies House.
Who needs alternative software
You filed through HMRC’s service last year
You typed your figures into HMRC’s online forms and sent your accounts and Company Tax Return from there. That route has gone, so this year’s return needs software.
You’re about to file a first return
A new company that has had a notice to deliver a Company Tax Return can no longer start with HMRC’s free service. It files through software from the first return.
Your accountant files for you
Nothing changes for you if they file through commercial software. Ask them if you’re not sure how last year’s return was sent.
What you used to do, and what you do now
With HMRC’s service
Prepare the accounts → enter the figures into HMRC’s forms → submit.
With A4O Accounts
Books → accounts → CT600 → file. Each step is built from the one before, so nothing is typed in twice.
How to move to A4O Accounts
1. Create an account and add your company
Add it by name, then enter the company number, Companies House authentication code and your 10-digit UTR on its page. The authentication code is stored encrypted.
2. Bring in last year’s closing position
Set the opening balance date and enter the balances from your last accounts as a journal. Have last year’s balance sheet, any losses carried forward and your capital allowance pools to hand.
3. Import your bank statements
Download them from online banking as CSV, Excel or OFX files, import them, and check the account suggested for each line before posting.
4. Prepare the accounts and the return
At the year end, the accounts are built from the books, the tax computation starts from the accounts profit, and the CT600 is filled in from the computation.
5. Test, then file
Send a test submission first. Then file the CT600 with HMRC using your Government Gateway user ID and password, and the accounts with Companies House as a separate filing.
Want a hand?
We’ll help with your first import. Email us and we reply within one working day.
What you’ll need: your UTR and Government Gateway details, your Companies House authentication code and your bank statements.
How much?
Create an account, add your company and file for real, with no card and nothing to pay. If we ever introduce paid plans, we’ll tell you at least 30 days before anything changes.
Can I file a real return?
Yes. Corporation Tax and Companies House filing are both live. The CT600 goes to HMRC with the accounts and computation in iXBRL, and the accounts go to Companies House as a separate filing. Either can be sent as a test submission first, so you can see it pass before filing for real.
What isn’t supported
So you know before you start.
Supplementary pages other than CT600A and CT600L
Loans to participators (CT600A) and research and development (CT600L) are supported. Other supplementary pages aren’t yet.
Group and consolidated accounts
Group accounts with intra-group eliminations aren’t supported.
Paying your Corporation Tax
Filing the return doesn’t pay HMRC. You pay the tax separately, as before.
Making Tax Digital
Built, and waiting for HMRC approval. It stays marked Coming soon until it’s switched on. Payroll (PAYE) is live.
How we look after your data
Your HMRC password isn’t kept
When you file a Corporation Tax return, your Government Gateway password is used for that submission and never stored. The copy of each submission we keep has the credentials removed.
Sensitive details are encrypted
Companies House authentication codes and HMRC and bank access tokens are encrypted in our database with AES-256-GCM. Passwords are hashed with bcrypt, and repeated failed sign-ins lock the account.
Every filing is logged
Each submission, and each change to key records, is logged with who made it and when, and the app has no way to edit or delete those records. Only a Manager on the company can submit a filing.
Common questions
When did HMRC’s free filing service close?
The “File your accounts and Company Tax Return” online service closed on 31 March 2026. From 1 April 2026, GOV.UK says to use commercial software to file annual accounts and Company Tax Returns with HMRC.
Can I file a real Company Tax Return with A4O Accounts?
Yes. Corporation Tax filing is live. The CT600 goes to HMRC with your accounts and tax computation in iXBRL, and you can send a test submission first.
How much does it cost?
Nothing to get started, including filing, and you don’t need a card. If we ever introduce paid plans, we’ll tell you at least 30 days before anything changes.
Have my deadlines changed?
No. The Company Tax Return is still due 12 months after the end of the accounting period, and Corporation Tax is usually due 9 months and 1 day after it. Accounts for a private company are due at Companies House 9 months after the financial year end.
Do I still file accounts with Companies House?
Yes. Accounts go to Companies House separately from the return you send HMRC. A4O Accounts files them as their own submission, with the company’s authentication code, from the same books.
Do I have to keep my bookkeeping in A4O Accounts?
Yes. The accounts and the return are built from the books in A4O Accounts, so there’s no form to type final figures into. Enter your opening balances as a journal and import your bank statements to get the year in.
Read next
Prepare your Corporation Tax return.
Add your company, bring in the books and file this year’s return with HMRC.
No card required. Need a hand? Email us.