If you’re a small business owner or company director in the UK, a major change is coming to how you file your annual accounts and Company Tax Returns. HMRC and Companies House have announced the closure of the joint filing service that allowed businesses to submit company accounts and tax returns at the same time.

🔗 Official HMRC Update

🔒 What’s Changing?

As of 31st March 2026, the Company Accounts and Tax Online (CATO) service will be permanently closed. This service allowed small companies and micro-entities to file their annual accounts to Companies House and a Company Tax Return to HMRC in one simple online process.

This joint filing option was convenient for many small businesses, particularly those not using accounting software.

However, due to evolving technology and increased reliance on digital recordkeeping, HMRC is now phasing out this legacy service.

📅 Key Dates to Remember

Milestone Date
Last day to use the joint filing service 31 March 2026
Service officially closes 1 April 2026
Deadline to download past submissions 31 March 2026

After 31 March 2026, you will no longer be able to access previously submitted returns through the joint filing service. It’s crucial to download and save copies of your past filings before this date as well as close down your corporation tax services with HMRC .GOV.UK+2

Need Help Closing Down HMRC Service?

🧾 HMRC-Recognized Commercial Software Options

With the closure of HMRC’s joint filing service, businesses will need to transition to commercial software to file their Company Tax Returns. HMRC provides a list of recognized software suppliers that can produce one or more elements of a Company Tax Return, including the CT600 form, computations, and company accounts.GOV.UK

You can find the full list of HMRC-recognized commercial software suppliers for Corporation Tax here:
👉 Commercial software suppliers for Corporation Tax GOV.UK

Additionally, for filing company accounts with Companies House, you can refer to their list of software options:
👉 Find software for filing company accounts – GOV.UK 

It’s important to choose software that meets your company’s specific needs and ensures compliance with HMRC and Companies House requirements.

Here’s a curated list of the top 10 HMRC-recognised commercial software providers for filing Company Tax Returns and accounts, based on usability, popularity among small businesses and accountants, compliance with UK regulations, and post-2026 readiness:

🔟 Top 10 Software Providers for Filing UK Company Tax Returns

Provider Best For Notable Features
FreeAgent Freelancers & small businesses MTD-ready, HMRC-recognised, user-friendly interface
Taxfiler (IRIS) Accountants & small firms Handles CT600, iXBRL tagging, detailed reporting
Xero Growing SMEs CT filing via integrations, real-time bookkeeping
QuickBooks Beginners & small businesses Simplified workflows, HMRC integrations
Sage Accounting Mid-sized businesses Tax and VAT tools, scalable features
Capium Accountants & multi-client practices Cloud suite, direct filing, compliance tools
BTCSoftware Accountants & tax pros Advanced compliance, CT600 support
Nomisma Small practice accountants Integrated CT600 & accounts prep
TaxCalc Professional users CT compliance, powerful calculations, desktop-based
Clear Books Micro-businesses & sole directors Cloud-based, HMRC-recognised, accounting features

Can’t decide on which to choose…? Lets see deep comparison 

Here’s a visual comparison table highlighting key features of the top HMRC-recognised tax software providers — especially relevant for company directors, accountants, or business owners transitioning from HMRC’s closed joint filing service:

    Software CT600 Support iXBRL Filing HMRC Recognised MTD Ready Price Range (Monthly) Ideal For
    FreeAgent £14–£36 Freelancers, SMEs
    Taxfiler (IRIS) From £20 Accountants, tax pros
    Xero ✅* ✅* £15–£55 + add-ons Growing SMEs
    QuickBooks ✅* ⚠️ £12–£30 + add-ons Sole traders, SMEs
    Sage Accounting ✅* ✅* £14–£30 Mid-sized businesses
    Capium Custom pricing Accounting firms
    BTCSoftware From £25+ Tax professionals
    Nomisma £15–£25 Small firms, agents
    TaxCalc From £22 Compliance-heavy firms
    Clear Books £12–£30 Micro-businesses

    * Some features (like CT600 or iXBRL) may require third-party add-ons or integrations. Always confirm with the software provider.

    Notes:

    • CT600 Support = Ability to file Corporation Tax returns.

    • iXBRL Filing = Required format for submitting accounts to HMRC.

    • MTD Ready = Compatible with Making Tax Digital requirements.

    • Pricing may vary based on number of users, clients, and modules.

      📌 Final Thoughts

      All companies and Tax fillers must download old returns and close down their service accounts with HMRC before deadline and transit to new software of choice before losing data and be on the safe side, Closure of the service to file your company accounts and tax return