Changes to Corporation Tax Filing from April 2026

From 1 April 2026, HMRC will formally close its free online filing service currently used for submitting Corporation Tax returns (CT600’s) and annual accounts. This marks a significant shift in how companies interact with HMRC, and it is important that all businesses are aware of the upcoming change to avoid any disruption to their statutory compliance obligations.

What happens once the existing service is withdrawn?

Once the existing service is withdrawn, all CT returns and accompanying accounts must be filed using commercial software that is recognised and supported by HMRC. HMRC has explained that the decision to close the platform is driven by the fact that it no longer meets modern digital standards or aligns with recent changes in company law. Commercial software products, generally provide a wider range of features designed to help businesses manage their compliance more efficiently. These may include deeper validation checks to help reduce the risk of errors, built in tax guidance, prompts and alerts for key deadlines, and automated data transfer from accounting systems. Collectively, these tools can make the filing process more accurate and significantly reduce the administrative burden on businesses, and margin for error.

As the online system is no longer accessible from 1 April 2026, this means that historical information will also no longer be accessible via the portal. It was recommended that all customers logged in to the HMRC online filing service before 31 March 2026 to download and save copies of at least the last three years of fi led returns. Ensuring you have secure copies of your previous submissions will help protect your records for future reference, HMRC queries, or professional reviews.

Is managing company compliance in-house still right for you?

For many businesses, this change may feel like a natural point to reassess whether managing Company compliance in-house remains the most efficient approach. Transitioning to new software, keeping up with evolving tax legislation, and ensuring filings remain accurate can all be time consuming and resource intensive. Appointing a professional advisor can provide valuable reassurance and practical support to businesses. In addition to managing the technical aspects of CT filings, an advisor can help identify tax saving opportunities, ensure compliance with the latest rules, streamline record keeping processes, and reduce the risk of penalties arising from late or incorrect submissions. Advisors also act as a point of contact with HMRC, which can save considerable time and provide businesses with confidence that their tax affairs are being handled correctly.

Get In Touch

If these changes are likely to affect you, and you feel now is a good time to appoint an advisor, please contact us at Whitings LLP. We would be happy to discuss how we can support you and your business.

Disclaimer - All information in this post was correct at time of writing.