File the Company Tax Return (CT600)
The Company Tax Return must be filed with HMRC within twelve months of the end of the accounting period, with the accounts and computations attached.
Is this you?
Every limited company that HMRC has asked for a return, which is every active company.
The detail
The return comes from the same accounts as the Companies House filing and the tax payment, so in practice all three are done together, well inside the twelve months.
What it costs
For a return due on or after 1 April 2026: £200 the day after the deadline and another £200 at three months, then 10% of the unpaid tax at six months and another 10% at twelve. A third consecutive late return raises the two £200 penalties to £1,000 each.
For a return due before 1 April 2026 the fixed penalties were £100 and £100, or £500 each for a third consecutive late return. Source: gov.uk and Companies House guidance, checked September 2026.
Now
Enter your year end below for the date. Buzz files the return with the accounts, months before this deadline.
In the same area
- Depends on your datesPay Corporation TaxCorporation TaxDetails
