Dormant Return File for £5

Late CT600 penalties: yes, they apply to dormant companies

By Max Szolcek, founder of Dormant Return. Last updated 21 August 2026

The most expensive misunderstanding in dormant company admin: "the company owes no tax, so a late return cannot cost anything." Late filing penalties for a Company Tax Return are fixed and automatic. HMRC's guidance states plainly that a penalty may be charged even if the company does not owe any Corporation Tax.

The penalty ladder

Where HMRC has issued a notice to deliver a Company Tax Return and the return misses its deadline, penalties accrue as follows (per gov.uk at the time of writing):

Time after the deadlinePenalty
1 day£200
3 monthsAnother £200
6 months10% of the unpaid tax (HMRC estimates the bill)
12 monthsAnother 10% of any unpaid tax

And the repeat-offender rule: if the return is late three times in a row, the £200 flat penalties increase to £1,000 each.

What this means for a genuinely dormant company

The tax-geared penalties at 6 and 12 months are 10% of unpaid tax, and 10% of zero is zero. So a dormant company's exposure is the flat penalties: £400 within three months of missing a deadline, or up to £2,000 for a company that has been serially late. For a company that has never earned a penny, those are real amounts of the director's own money, because someone has to fund the company to pay them.

At 6 months late there is a second nuisance: HMRC raises a tax determination, its own estimate of what the company owes, and can pursue it until the actual return showing the nil position is filed. Even for a dormant company, the only way to close the loop is to file.

The deadline

A Company Tax Return is due 12 months after the end of the accounting period it covers. The two flat penalties therefore land at 12 months and one day, and at 15 months, after the period end. Your company's exact obligations and dates are listed in its HMRC business tax account.

How to stop the clock

Only one thing stops late filing penalties accruing further: filing the return. Since HMRC's free service closed on 31 March 2026 that means commercial software (see your options after the closure); for a dormant company the return itself is small, a CT600 of zeroes with iXBRL dormant accounts, and the process takes minutes (see how to file a dormant company CT600 online).

If you believe the company should never have been asked for a return at all, because it has been dormant throughout and HMRC simply does not know, it is sometimes possible to get the notice withdrawn by telling HMRC the company is dormant; but if HMRC maintains the notice, the return remains due and penalties keep accruing while you argue. Filing the nil return first is often the pragmatic move.

You can appeal a penalty if you have a reasonable excuse, but "the company was dormant" is not by itself a reasonable excuse for missing a deadline HMRC set.

Deadline looming, or already passed? Dormant Return files the CT600 and dormant accounts straight to HMRC in about five minutes, for £5. Filing is the only thing that stops the penalty ladder.

Start your return

Related guides

Sources