HMRC’s free company filing service closes on 31 March 2026

Finance & Funding

In a nutshell...

The free HMRC/Companies House joint filing service ends on 31 March 2026, and past filings held in the system will no longer be available.
From 1 April 2026, you must use commercial software to file your Corporation Tax return (CT600) – the CATO portal will not accept submissions.
All companies – including CICs and micro entities – will be required to move to software only accounts filing by 1 April 2027.

HMRC will close its free Company Accounts and Tax Online (CATO) service on 31 March 2026, meaning all companies must switch to commercial software for filing Corporation Tax returns from 1 April 2026. Past filings stored in the old system will no longer be accessible, so it’s important to download what you need and prepare early. In this article, we’ll cover who this affects, what you need to know, and what you need to do now.

Why the free service is closing

HMRC has said the service no longer meets modern digital standards and does not align with reforms introduced under the Economic Crime and Corporate Transparency Act, which aims to modernise the UK’s filing systems and strengthen identity verification and anti fraud controls.

The Government confirmed in May 2025 that no free commercial filing software is available, although low-cost options exist. This affects all small businesses and CICs.

What’s changing from April 2026

Corporation Tax Returns must be filed using commercial software

From 1 April 2026, HMRC will only accept CT600 submissions made via recognised commercial software.

CATO is being switched off permanently

You can file or amend returns until 31 March 2026, but after that you will lose the ability to access previously filed CT600s or accounts.

Accounts filing changes continue into 2027

Companies House will allow WebFiling and paper filings through 2026, but plans to move to software-only account filing from 1 April 2027. This includes accounts for small companies, micro entities and dormant companies.

What you must do before 31 March 2026

All businesses using the free service should:

Download past filings (at least the last 3 years) – After 31 March 2026, you cannot retrieve historical records through the CATO system.
Start choosing new software early – You do not need to register your software choice with HMRC. Simply begin using a new system before your next Company Tax Return or accounts filing deadline.

To download your past filings:

Sign in to the HMRC service.
Open “Track your submissions”.
Choose the filing period.
Select the HMRC or Companies House submission link.
Click “Save your return in HTML”.

How to choose the right software

When selecting software, consider:

Compliance and features

Choose a product that supports:

CT600
Corporation Tax (CT) computation
iXBRL tagging
(Ideally) combined filing to Companies House

Integration with bookkeeping

Linking to cloud accounting software can simplify year end work.

Workflow and ease of use

Look for:

Built-in validation checks
Guided workflows
Error flags, to help reduce filing risks

Access controls

Useful for teams who need reviewer roles, audit trails and e signing.

Future readiness

Ensure your chosen product is prepared for upcoming changes including software only account filing from April 2027.

CICs: What Community Interest Companies need to know

These changes apply to all companies, but CICs have a few additional considerations worth noting.

CICs must also move to commercial software from April 2026

All CICs, regardless of size, will need commercial software for Corporation Tax and company accounts from 1 April 2026. There will be no free options.

CICs can currently file accounts and the CIC34 report by post. Companies House has confirmed that paper and web filing routes for accounts will close on 1 April 2027 as part of wider company law reforms, meaning all CICs – including micro entities – will need to use commercial software from that point.

Identity verification rules apply

All directors must verify their identity under ECCT Act reforms. This applies to CICs of all sizes.

Looking Ahead: Changes from April 2027

Companies should prepare early for the next wave of filing reforms coming into force from April 2027:

Software only account filing for all companies
Expanded reporting requirements for small and micro entities
Removal of “abridged accounts”
Enhanced audit exemption statements

See UK Government guidance for more information.

Next steps…

Find out more about how to choose and get the best out of cloud accounting software.
Explore finance software options to help your business stay compliant.
If you need accountancy support, find out more about The Accountancy Partnership discounts for start-ups and established businesses.
Consider joining Founder Pass, giving you access to amazing discounts on a range of business essentials, including accounting software.