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Companies House Online Accounts Filing Changes: What Businesses Need to Know Before 2026

Businesses that rely on Companies House online accounts filing should prepare for significant changes as the Online Accounts and Company Tax Return (CATO) service is scheduled to close on 31 March 2026. The closure marks an important shift in how companies submit accounts and tax information to Companies House and HMRC.

For many years, the CATO service allowed businesses to file company accounts and Corporation Tax returns simultaneously through a single platform. However, changes in company law, increasing digital compliance requirements, and the government’s wider modernisation strategy mean businesses will soon need to adopt alternative filing methods.

Understanding these changes early can help companies avoid disruption, maintain compliance, and ensure a smooth transition to modern digital filing systems.

Review Your Companies House Filing Process

What Is the CATO Service?

The Online Accounts and Company Tax Return service, commonly known as CATO, was developed to simplify compliance by allowing businesses to submit company accounts to Companies House and Corporation Tax information to HMRC through one online process.

The service was particularly useful for smaller companies that wanted a straightforward solution for meeting annual filing obligations without investing in commercial accounting software.

Businesses moving away from CATO should also ensure the transition does not create gaps in how their tax position is managed taking time to build a solid understanding of corporation tax, including how it is calculated and what companies are required to report to HMRC, sits alongside any practical changes being made to the filing process.

However, as digital reporting requirements have evolved, the service has become increasingly outdated compared to modern accounting and compliance systems.

Why Is Companies House Ending the Service?

The decision to discontinue the service is linked to broader reforms affecting UK corporate reporting and transparency.

Recent legislative changes introduced through the Economic Crime and Corporate Transparency Act have expanded the role of Companies House and strengthened its powers to improve the accuracy and reliability of company information.

At the same time, HMRC continues to encourage businesses to adopt digital record-keeping and reporting practices through initiatives such as Making Tax Digital.

As a result, older filing systems no longer align with the government’s long-term digital strategy.

How Will Companies House Online Accounts Filing Work After March 2026?

Following the closure of CATO, businesses will need to use approved commercial software for companies house online filing and Corporation Tax reporting.

Many accounting software providers already offer integrated solutions that allow companies to prepare accounts, maintain financial records, and submit required filings electronically.

The move towards software-based reporting is expected to improve efficiency, increase accuracy, and reduce filing errors.

Businesses that are not ready to move to commercial software immediately should also be aware that Companies House WebFiling remains available for certain statutory submissions in the interim. Understanding how Companies House WebFiling works and what it can be used for helps businesses maintain compliance during the transition period without leaving statutory filings unmanaged while a longer-term software solution is being put in place.

Benefits of Modern Filing Software

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Key Actions Businesses Should Take Before the Closure

Although the deadline may seem some time away, businesses should begin planning for the transition now.

The same principle applies to account submissions more broadly businesses that make a habit of filing accounts ahead of their statutory deadline are consistently better placed to absorb unexpected disruptions, whether from software changes, technical issues, or administrative delays. The transition away from CATO makes early filing an even more sensible approach than usual during this period.

Download Previous Filing Records

Companies should download and securely store copies of previous filings submitted through the CATO service.

Current guidance recommends retaining at least three years of filing history before the service closes, as historical submissions may no longer be accessible after 31 March 2026.

Review Your Current Compliance Processes

This is an ideal opportunity to review existing accounting and compliance procedures to ensure they remain suitable for future digital reporting requirements.

Businesses that still rely heavily on manual processes may benefit from moving towards integrated cloud accounting solutions.

This review should also include confirming whether any changes to the company’s accounting year-end have been made recently, as altering the accounting period directly affects when annual accounts and Corporation Tax returns fall due. A year-end change that has not been properly carried across into a new software setup can mean the system is tracking the wrong filing deadline from day one  which is one of the more avoidable compliance risks during any platform transition.

As part of this compliance review, businesses should also confirm that all event-driven reporting obligations are being handled correctly alongside annual filing requirements. Certain changes to company directors, registered office, or ownership structure must be reported to Companies House within specific timeframes as they occur and understanding exactly what company changes must be reported, and when, is a separate but equally important part of maintaining clean statutory records.

Choose Suitable Accounting Software

Selecting software that supports both HMRC and online filing Companies House requirements will help ensure a smooth transition.

Smaller companies should also use this transition as an opportunity to confirm their position on filing abridged accounts, as the rules around simplified reporting formats are changing alongside the wider filing reforms. Selecting software that supports the correct accounts format for the company’s size and eligibility avoids the risk of submitting the wrong type of accounts through the new platform.

When evaluating software providers, businesses should consider:

Businesses selecting new software should also ensure it supports the updated confirmation statement process, as recent confirmation statement changes have introduced new requirements around what must be declared and how the filing is completed. Choosing a platform that has not been updated to reflect these changes could result in non-compliant submissions even where the software otherwise meets Companies House standards.

Filing Accounts Online at Companies House: What Businesses Need to Know

The process of filing accounts online at Companies House will continue after the CATO service closes. The main difference is that businesses will use commercial software rather than the existing government platform.

Companies will still need to prepare annual accounts accurately and submit them within the required deadlines and the transition to new software is a good moment to review the full scope of company filing obligations that apply throughout the year, not just the accounts submission itself.

Failure to comply with filing obligations can result in penalties, enforcement action, and reputational damage.

How Does This Relate to Making Tax Digital?

The closure of the CATO service supports the government’s wider Making Tax Digital programme, which aims to modernise tax administration through technology.

Making Tax Digital encourages businesses to maintain digital records and use compatible software to improve the accuracy of tax reporting.

The move away from older filing systems reflects this ongoing shift towards a more connected and digitally focused compliance environment.

Companies House File Accounts Online: Common Compliance Risks

Businesses that Companies House file accounts online should remain aware of several common compliance risks during the transition period.

Taking proactive steps now can help minimise disruption and reduce the risk of future compliance issues.

The financial consequences of these risks have also become more serious from April 2026, late filing penalties for limited companies have risen considerably, meaning a missed deadline during the transition period carries a higher financial cost than it would have in previous years. Businesses that are already managing a software transition cannot afford to let deadline management slip at the same time.

Recent Developments Affecting Online Filing

The Economic Crime and Corporate Transparency Act continues to drive significant changes within Companies House. These reforms aim to improve corporate transparency, strengthen identity verification procedures, and enhance confidence in the information held on the public register.

Businesses should expect further digitalisation of filing processes in the coming years as Companies House continues implementing these reforms and staying informed about the changes to online filing of accounts at Companies House is an ongoing responsibility, not a one-off review, as requirements continue to evolve alongside the wider corporate transparency programme.

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Conclusion

The upcoming changes to Companies House online accounts filing represent an important step in the UK’s transition towards fully digital corporate reporting. While the closure of the CATO service will require businesses to adopt new filing methods, it also provides an opportunity to improve efficiency, accuracy, and compliance.

By downloading previous filings, reviewing compliance procedures, and adopting suitable software early, businesses can ensure a smooth transition and continue meeting their reporting obligations with confidence.

One obligation that runs entirely separately from the Companies House transition is Corporation Tax payment HMRC’s payment deadlines are unaffected by any changes to filing platforms, and businesses focused on managing the CATO closure should ensure their tax payment process remains on track in parallel. Knowing how to pay Corporation Tax online and confirming that the correct payment method and deadline are in place is a straightforward but essential step that should not be overlooked during a period of wider compliance change.

Streamline Your Companies House Accounts Filing With Support From Cigma Accounting in London

Managing companies house online accounts filing efficiently is essential for businesses that want to meet reporting obligations and avoid unnecessary compliance issues. Cigma Accounting supports companies throughout Fulham Broadway, including businesses operating in Parsons Green and Walham Green, helping directors understand changing filing requirements and maintain accurate statutory records.

Whether you are filing accounts online at Companies House for the first time or reviewing an existing reporting process, staying compliant requires careful attention to deadlines and submission standards. Our team provides practical guidance on companies house online filing, helping businesses prepare statutory information correctly, reduce filing risks, and manage their reporting responsibilities with greater confidence.

Frequently Asked Questions About Companies House Online Accounts Filing

What is Companies House online accounts filing?



Companies House online accounts filing allows UK companies to submit their annual accounts electronically through approved digital channels. It provides a faster, more secure, and more efficient alternative to paper filing while helping businesses meet statutory deadlines.

To file accounts online at Companies House, you must prepare compliant accounts, access an approved filing service or software, enter the required information, and submit the accounts electronically before the filing deadline.

Yes. Companies House continues to expand digital filing requirements as part of wider corporate transparency reforms. Businesses are increasingly encouraged to use online filing methods to improve accuracy, security, and data quality.

Most UK limited companies can file accounts online. However, eligibility may depend on the company type, accounting framework used, and the complexity of the accounts being submitted.

Late filing can result in automatic penalties from Companies House, increasing with the length of the delay. Persistent non-compliance may also affect a company’s reputation and regulatory standing.

Generally, yes. Companies House online filing includes authentication measures and electronic submission tracking, making it more secure and reducing the risk of lost or delayed documents.

Companies House online accounts filing allows UK companies to submit their annual accounts electronically through approved digital channels. It provides a faster, more secure, and more efficient alternative to paper filing while helping businesses meet statutory deadlines.

To file accounts online at Companies House, you must prepare compliant accounts, access an approved filing service or software, enter the required information, and submit the accounts electronically before the filing deadline.

Yes. Companies House continues to expand digital filing requirements as part of wider corporate transparency reforms. Businesses are increasingly encouraged to use online filing methods to improve accuracy, security, and data quality.

Most UK limited companies can file accounts online. However, eligibility may depend on the company type, accounting framework used, and the complexity of the accounts being submitted.

Late filing can result in automatic penalties from Companies House, increasing with the length of the delay. Persistent non-compliance may also affect a company’s reputation and regulatory standing.

Generally, yes. Companies House online filing includes authentication measures and electronic submission tracking, making it more secure and reducing the risk of lost or delayed documents.

Keep Your Company Accounts Filing Accurate and Compliant

Companies House filing requirements continue to evolve, making accurate online reporting increasingly important for UK businesses. Cigma Accounting helps companies across Fulham Broadway and surrounding commercial areas manage online accounts submissions, meet statutory deadlines, and maintain compliance through reliable accounting and advisory support.


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CIGMA Accounting Ltd is a forward-thinking accounting and tax firm based in London, dedicated to delivering high-quality compliance, tax planning, and business advisory services to entrepreneurs, landlords, and growing SMEs. With offices in Wimbledon and Farringdon, we combine local expertise with a tech-driven approach to simplify accounting. Our services include corporation tax filing, VAT compliance, HMRC investigation support, R&D tax credit claims, capital allowances optimisation, and bookkeeping automation. What sets CIGMA apart is our ability to blend traditional accounting rigour with AI-powered systems that reduce errors, save time, and provide real-time financial insights. Our team ensures that every client - from startups to high-net-worth individuals - receives a bespoke solution aligned with their growth goals. Whether you need strategic tax planning, help with HMRC disclosures, or a full outsourced finance function, CIGMA Accounting delivers clarity, compliance, and confidence.