Published July 2026 | The Finance Guide
If you’re a UK limited company director who just discovered that HMRC’s free filing portal (CATO — Company Accounts and Tax Online) has been permanently shut down, you’re not alone. I found myself in exactly the same position this week, with accounts overdue at Companies House and a CT600 deadline fast approaching.
Here’s exactly how I solved it — quickly, cheaply, and without an accountant.
What Was CATO and Why Does It Matter?
For years, HMRC provided a free GOV.UK service called CATO (Company Accounts and Tax Online) that allowed UK limited company directors to file their CT600 Corporation Tax return and annual accounts directly with HMRC and Companies House. It was free, it worked, and tens of thousands of sole directors and small business owners across England, Scotland, Wales and Northern Ireland relied on it.
On 31 March 2026, HMRC closed it permanently.
No CATO means you can no longer file directly through HMRC’s own portal. You now need HMRC-recognised third-party software to submit your CT600 Corporation Tax return and iXBRL annual accounts. Most UK directors’ first instinct is to panic and call an accountant — but that’s not necessarily your only option, particularly if your company is a straightforward micro-entity.
My Situation
I run a small limited company registered at Companies House. For years I used bookkeeping software to manage my accounts and CATO to submit. Simple, free, effective.
When I discovered CATO was gone, I had accounts overdue at Companies House and a CT600 deadline approaching fast. As a sole director, I needed a solution that:
- Didn’t require a monthly SaaS accounting subscription
- Didn’t require hiring an accountant or tax agent
- Let me continue using my existing bookkeeping setup
- Was genuinely affordable for a UK micro-entity
After researching the options available to UK limited company directors, I found TinyTax.
What Is TinyTax?
TinyTax (tinytax.co.uk) is a UK-built, HMRC-recognised online tool specifically designed for small limited company directors to file their CT600 and FRS105 micro-entity accounts themselves. It is recognised by both HMRC and Companies House as approved filing software.
What makes it different from the big cloud accounting platforms like Xero or QuickBooks:
- No monthly subscription — you pay annually per company
- Built for UK micro-entities — straightforward, no unnecessary accountancy jargon
- Files to both HMRC and Companies House simultaneously in one submission
- You can prepare everything for free — you only pay when you actually hit submit
- Generates iXBRL accounts automatically — the machine-readable format now required by both HMRC and Companies House
The Pricing
TinyTax pricing is simple, transparent, and significantly cheaper than a UK accountant:
| Plan | Cost | Companies |
|---|---|---|
| Dormant | £20 + VAT/year | 1 dormant company |
| Solo | £59 + VAT/year | 1 trading company |
| Portfolio | £99 + VAT/year | Up to 3 companies |
For most UK limited company directors with one trading company, the Solo plan at £59 + VAT = £70.80/year is all you need. Compare that to a UK accountant typically charging £500–£1,500 per limited company for the equivalent work.
If you have two or three companies to file, the Portfolio plan at £99 + VAT works out at just £33 per company — even better value.
All prices exclude VAT. If your company is VAT-registered, you can reclaim the VAT as an input tax credit.
How I Filed — Step by Step
Step 1 — Prepare Your Figures from Your Bookkeeping Software
TinyTax doesn’t replace your bookkeeping software. You still prepare your accounts in whatever you currently use — whether that’s a desktop accounting package, a spreadsheet, or cloud software — then enter the final year-end figures into TinyTax. Think of it as the digital submission layer sitting on top of your existing bookkeeping process — exactly the role CATO used to play.
From my bookkeeping software I ran two standard reports:
- Profit & Loss for the full financial year
- Balance Sheet as at the year end date
That’s all you need.
Step 2 — Create a TinyTax Account and Find Your Company
Go to tinytax.co.uk and sign up with your email address. Search for your limited company by name — TinyTax pulls your registered details directly from the Companies House register automatically, including your registered office address, directors, and accounting period dates.
Step 3 — Enter Your Figures
TinyTax walks you through a clean, logical form that mirrors the structure of UK statutory accounts under FRS105 (the micro-entity reporting standard):
- Profit & Loss section — enter your turnover, cost of sales, overheads, and depreciation
- Balance Sheet section — enter your fixed assets, current assets, creditors, and capital and reserves
- Tax Computation — TinyTax automatically calculates your Corporation Tax liability at the current UK rate of 19%
The whole data entry process took me under an hour, including double-checking figures against my bookkeeping printouts.
Step 4 — Review Your Documents
Before paying anything, TinyTax generates all four documents you need for a compliant UK filing:
- Full Accounts — including P&L, for shareholders and your own records
- Filleted Accounts — machine-readable iXBRL format for Companies House (this is the format that CATO used to generate for you)
- Tax Computations — detailed corporation tax calculations for HMRC
- CT600 Form — your Corporation Tax return in the traditional paper layout, filed digitally
You can download and review all four documents completely free before committing to pay a penny.
Step 5 — Subscribe and Submit
Once you’re satisfied everything looks correct, subscribe to the relevant plan and submit. You’ll need two sets of credentials:
For HMRC (CT600 Corporation Tax return):
- Your company’s UTR — Unique Taxpayer Reference (10-digit number found on any HMRC letter addressed to your company, or in your HMRC Business Tax Account on GOV.UK)
- Government Gateway User ID
- Government Gateway password
For Companies House (Annual Accounts):
- Your company’s 6-character authentication code (issued by Companies House to your registered office address)
Both submissions complete in about two minutes. You receive an instant acceptance confirmation with a unique reference number from both HMRC and Companies House — your proof of filing.
Who Is TinyTax Suitable For?
TinyTax works for UK private limited companies filing as micro-entities under FRS105. To qualify as a micro-entity your company must meet at least two of the following three criteria in both the current and prior financial year:
- Annual turnover under £1 million
- Balance sheet total under £500,000
- Fewer than 10 employees
This covers the vast majority of owner-managed limited companies registered at Companies House across the UK — sole director consultancies, property holding companies, small trading businesses, and dormant companies.
TinyTax is not suitable for larger companies, registered charities, Community Interest Companies (CICs), or companies that don’t meet the micro-entity thresholds above.
What About MTD — Making Tax Digital?
There is significant confusion among UK limited company directors between the CATO closure and Making Tax Digital. They are entirely separate HMRC programmes:
- CATO closure — affects how you file your annual CT600 and statutory accounts. Closed 31 March 2026. You need new software now.
- MTD for VAT — mandatory digital VAT return filing via HMRC-recognised software. Already required for all VAT-registered businesses regardless of turnover.
- MTD for Corporation Tax — a future HMRC programme that will eventually require quarterly digital updates alongside your annual CT600. Not yet mandatory for most limited companies.
TinyTax handles your annual CT600 and Companies House accounts filing — which is what every UK limited company director needs to address right now following the CATO closure.
Frequently Asked Questions
Can I still use my existing bookkeeping software? Yes. Continue using whatever bookkeeping software or spreadsheets you currently use exactly as you do now. TinyTax only needs your final year-end P&L and Balance Sheet figures — you enter those manually and TinyTax handles the rest.
What if my previous years were filed through CATO? TinyTax handles this cleanly. When you add your company it will ask about prior periods. If you’ve already filed previous years through CATO or another route, simply mark them as filed elsewhere and proceed with the current year.
Do I need an accountant to use TinyTax? No. TinyTax is specifically designed for sole directors and small business owners to use themselves without professional help. That said, if your affairs are complex — multiple directors, group structures, R&D claims, or significant capital allowances — it may be worth involving an accountant.
What is iXBRL and do I need to understand it? iXBRL (Inline eXtensible Business Reporting Language) is the machine-readable format now required by HMRC and Companies House for digital accounts submission. TinyTax generates your iXBRL accounts automatically from the figures you enter — you never need to understand or interact with the underlying format directly.
My Recommendation
If you’re a UK limited company director who:
- Previously used CATO and is now stuck following its closure
- Has straightforward accounts under the FRS105 micro-entity thresholds
- Wants to avoid expensive ongoing accountancy fees for a simple annual filing
- Is comfortable entering figures from your own bookkeeping records
TinyTax is the cleanest, most affordable HMRC-recognised solution I’ve found for UK limited company directors in this position. The fact that you can prepare everything and download all four documents before paying a penny makes it genuinely risk-free to try.
Get started at TinyTax here → https://tinytax.co.uk/?ref=E796R5AF
Quick Reference Checklist — What You’ll Need Before You Start
- [ ] Profit & Loss report for your full financial year (from your bookkeeping software or accountant)
- [ ] Balance Sheet as at your year end date
- [ ] Previous year’s filed accounts (for opening balance sheet comparison figures)
- [ ] Company UTR — 10-digit Unique Taxpayer Reference (on any HMRC letter or your GOV.UK Business Tax Account)
- [ ] Government Gateway User ID and password for the company
- [ ] Companies House authentication code (6 characters — issued to your registered office)
Disclosure: This post contains a referral link to TinyTax. If you subscribe using the link above, I receive a small commission at no extra cost to you. I only recommend tools I have personally used and paid for — I filed my own limited company accounts through TinyTax on the day this article was written.
Found this useful? Share it with any UK limited company director you know who may have been caught out by the CATO closure. There are thousands of sole directors across the UK in exactly this situation right now — and most don’t yet know there’s a straightforward, affordable solution available.
This article does not constitute financial or tax advice.
If you are unsure about your own tax affairs, consult a qualified accountant.