HMRC is Closing CATO—Here is Your Action Plan
The free Company Accounts and Tax Online service shuts down permanently on March 31, 2026. Secure your historical records and upgrade your filing software before the cliff edge.
The End of an Era for Unrepresented Companies
For years, thousands of small businesses have relied on HMRC's CATO service to file their company accounts and Corporation Tax returns in one place. It was free, it worked, but it is going away.
From April 1, 2026, the CATO portal will be switched off forever. You will no longer be able to submit new returns, amend old ones, or even view your historical filings.
What This Means for Your Business
If you wait until the deadline, you risk losing access to your critical financial history. You must take two actions immediately:
- Download your past data: Log into CATO today and save PDF copies of your last three years of tax returns and accounts. Once the portal closes, that data is gone.
- Find commercial software: HMRC is moving purely to commercial integrations. You will need third-party accounting software to file your CT600 returns moving forward.
Make the Switch to Automated Accounting
Filing your taxes shouldn't require a degree in accounting. While CATO's closure feels like an inconvenience, it is actually the perfect opportunity to modernize how your business handles its finances.
With ac-co.ai, you do not just get a basic filing tool. You get an intelligent system that categorizes your expenses, prepares your accounts, and submits your tax returns directly to HMRC and Companies House without the stress.
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