Changes to how you file your company accounts & company tax return
What is changing?
- The free joint online service provided by HMRC & Companies House, called File your company accounts AND Company Tax Return (sometimes called CATO / “Company Accounts & Tax Online”), will be ending on 31 March 2026.
- After this date, you will no longer be able to submit your accounts + Company Tax Return using this joint service.
- Companies House is also moving towards software-only filing, meaning paper forms and older online services will gradually disappear.
Why the change?
- The current joint service is considered outdated — it doesn't meet modern digital standards or the enhanced requirements for corporation tax and company law under the Economic Crime and Corporate Transparency Act.
- Moving to software-based and “tagged” electronic filings helps with accuracy, consistency, transparency, better validation, and helps to fight fraud/economic crime.
What this means for you
- If you currently use the joint service to file both accounts and your CT600, you’ll need to switch to using software after 31 March 2026.
- If your company’s accounting period ends after 31 March 2025, then for that accounting period (once the service ends) you’ll need to use commercial / third-party software or another approved route.
- You should download and save copies of your past filings (especially recent years) from the outgoing service before it closes, because after 1 April 2026 they will no longer be accessible via the old system.
The easy way forward
Our software takes care of all this seamlessly – from accounts to tax returns – so you don’t have to worry about the changes.