File company accounts and tax return online now CATO has closed

What was Company Accounts and Tax Online?

HMRC's own free online service for filing a Company Tax Return, sometimes called CATO. Many small companies used it once a year to send their CT600 straight to HMRC without buying software. HMRC closed it on 31 March 2026 (GOV.UK: filing after the HMRC online service closed), so it's no longer an option for periods filed from 1 April 2026 onwards.

What do you need to do now the service has closed?

Use commercial software, such as Taxley, to file your Company Tax Return. From 1 April 2026, HMRC says companies should use commercial software to file annual accounts and Company Tax Returns. The only other routes are narrow: a paper return if you have a reasonable excuse for not filing online, or if you're filing in Welsh (GOV.UK: filing after the HMRC online service closed) — otherwise HMRC expects an online return. There is no HMRC CATO software any more: HMRC doesn't run its own filing service now, so you use commercial software, such as Taxley, or an accountant.

Can Taxley file company accounts and tax return together?

Yes. Your Company Tax Return (CT600), the Corporation Tax computation and your iXBRL accounts go to HMRC with your own Government Gateway login, and the same accounts go to Companies House once the return is paid and finished. Taxley works out the main rate, the small profits rate and marginal relief, and prepares micro-entity (FRS 105) or small-company (FRS 102 Section 1A) accounts alongside the return.

Companies House accounts filing is live too. Once your Company Tax Return is paid and its accounts are finished, Taxley can send the same accounts to Companies House in the same visit, so the accounts and the CT600 are filed from one place.

For the detail, read our guides to filing company accounts with Companies House online, what goes in micro-entity accounts and Companies House late filing penalties. Directors also need to verify their identity with Companies House.

How much does Taxley cost?

One fee per return, charged only when you choose to file. The old HMRC service was free to use, but it's closed; Taxley's fee replaces the cost of buying commercial software, and preparing and previewing your whole return first is free. See the exact prices on the pricing page.

What doesn't Taxley do for a former Company Accounts and Tax Online user?

• file a paper Company Tax Return on your behalf, even where HMRC allows one for a reasonable excuse or a Welsh-language return;
• file uploaded accounts, accounts Companies House already has, first accounts whose period doesn't start on the incorporation date, or the confirmation statement — you file those at Companies House yourself;
• decide whether you qualify for a paper-filing exception — HMRC makes that decision, not Taxley;
• import data directly from the closed HMRC service — there's no transfer route, so you re-enter your company's details the first time.

If you're not sure filing it yourself is right for you, do I need an accountant? sets out what filing it yourself covers.

Frequently asked questions

Why did Company Accounts and Tax Online close?

HMRC replaced its own free filing service with commercial software from 1 April 2026. GOV.UK's closure guidance sets out the replacement routes for both the Company Tax Return and Companies House accounts.

Can I still file a paper Company Tax Return?

Only if you have a reasonable excuse for not filing online, or you're filing in Welsh. Otherwise HMRC expects an online return through commercial software such as Taxley.

Does Taxley file my accounts with Companies House?

Yes. Taxley files your accounts at Companies House, from the same figures as your return, once the CT600 return is paid and finished. You need the company's Companies House authentication code.

What did the old service used to file, and what does Taxley file?

The closed HMRC service filed the Company Tax Return (CT600), and sometimes the accounts alongside it. Taxley files the CT600, your accounts computation and iXBRL accounts to HMRC, using the company's own Government Gateway login.

How much does Taxley charge?

One fee per return, shown before you pay and charged only once you choose to file. Preparing and previewing your return first is free — see the exact prices on the pricing page.