Starting 1 April 2026, all businesses must use commercial software that is compliant with HMRC and Companies House regulations to file their company’s tax returns.
This follows the closure of the free joint online service, known widely as the CATO portal, on 31 March.
Company tax returns must now be filed to HMRC using compliant software, although it is currently still possible to file annual accounts at Companies House using third-party software, WebFiling services or paper filing.
These changes are part of a wider shift towards a digital-focused model that aims to remove services that are deemed to be outdated and unable to align with modern standards.
All of this has been made possible through the Economic Crime and Corporate Transparency Act and is designed to improve transparency and reduce the risk of fraud.
However, the bright future of digital services was marred recently by the data breach that saw the WebFiling system of Companies House vulnerable and allowed some users to potentially access and amend the details of other companies.
Can the free service still be used to amend previous returns?
Unfortunately, the free filing service has now closed and the only way to make changes to previously submitted Corporation Tax returns or refile rejected returns will be through the use of commercial tax software.
Previously filed financial information is not retained in the system and cannot be accessed, so it will need to be entered again as necessary.
A paper return is still acceptable for amendments and can be sent to the Corporation Tax Services office.
These changes are mirrored by Companies House and to make changes or corrections to previously filed financial accounts, it will be necessary to use commercial software or to send paper accounts to Companies House via post.
It is possible to file a paper Corporation Tax return in very niche situations, such as if you are submitting it in Welsh or if you have a valid, reasonable excuse as to why you should be exempt.
This will need to be explained to HMRC, who will then make the necessary adjustments.
Our team can help you to stay compliant as both HMRC and Companies House adjust their systems to align with the digital age, so be sure to get in touch.
