ArticleBy Matvei Kostiuchenko
HMRC's free Company Tax Return service has closed. What now?
The 'File your accounts and Company Tax Return' service closed on 31 March 2026. What changed, what you still have to file, and the three ways to do it.
If you have been filing your own CT600 through HMRC's website, that door is shut. The 'File your accounts and Company Tax Return' service closed on 31 March 2026. From 1 April, HMRC expects Company Tax Returns to come in through commercial software. Nothing else about your obligations changed: the same return, the same deadlines, the same penalties.
What closed, exactly
The joint HMRC and Companies House service let small companies type in their accounts and tax figures on GOV.UK, and it sent the accounts to Companies House and the CT600 to HMRC in one go. It was free, and for a simple company it was often the only tool a director ever touched.
HMRC's stated reason is that the service was outdated and did not fit newer digital standards, Corporation Tax requirements or the company law changes under the Economic Crime and Corporate Transparency Act. The old service is also gone as an archive: past filings made through it are no longer viewable there, so if you did not download your last three years of accounts before April, you now need them from your own records or from Companies House.
What you still have to file
Two filings, two bodies, and they are now separate:
| Filing | Who gets it | How |
|---|---|---|
| Annual accounts | Companies House | software, Companies House web filing, or paper |
| Company Tax Return (CT600, tax computation and accounts in iXBRL) | HMRC | software only |
The Companies House side still has a free web route. The HMRC side does not. A paper CT600 is only accepted if you have a reasonable excuse, or if you are filing in Welsh.
The three ways to file the CT600 now
1. Use an accountant. They file through their own software. For a company with real complexity (groups, R&D claims, property or overseas income) this is still the right answer. For a one-director company with a simple profit and loss it is often the most expensive way to fill in a form.
2. Buy full accounting software. The larger packages produce the accounts, the computation and the CT600, and many of them file with Companies House too. They are built for accountants and priced as such: annual licences, per-client fees and a learning curve that assumes you already know what a capital allowance pool is.
3. Use a filing-only tool. Software that takes your figures for the year, produces the tax computation and accounts in the iXBRL format HMRC requires, and files the CT600 directly with HMRC. This is the closest replacement for what the old service did for a simple company. It does not replace an accountant's judgement, and it does not file with Companies House.
HMRC publishes a list of commercial software suppliers for Corporation Tax. Check that whatever you pick covers all three parts, CT600, computation and accounts, because some products only do one.
What you need before you start
Whichever route you take, have these ready:
- Your company's Unique Taxpayer Reference (UTR) for Corporation Tax, not the personal one.
- Your Government Gateway user ID and password enrolled for Corporation Tax. The software files under your credentials; nothing goes to HMRC without them.
- The accounting period HMRC expects a return for. It normally matches your financial year and cannot be longer than 12 months.
- Your figures for the year: turnover, expenses, assets bought, any dividends and director's loan movements.
Where filefast fits
filefast is the third route. You add your company from the Companies House register, enter the year's figures, and it produces the computation and accounts in iXBRL, runs the checks HMRC's gateway would run, and files the CT600 directly with HMRC. It is built for the company the old service was built for: one trade, UK income, no group. If your return needs R&D relief, group relief or overseas income, it will tell you before you start rather than after.
You still file your accounts with Companies House separately; their web service remains free.
The deadline has not moved
The CT600 is due 12 months after the end of the accounting period, and the tax is usually due earlier, 9 months and 1 day after. Late filing starts at a £100 penalty on day one. If the closure caught you mid-year, the return is still expected on the same date; "the service closed" is not on HMRC's list of reasonable excuses.
Sources: Filing company accounts and tax returns if you previously used the HMRC online service, The online accounts and Company Tax Return service is closing and Company Tax Returns on GOV.UK.