Accounts & dormancy

HMRC wants a tax return from your dormant company. Now what?

A tax demand for a company that owes nothing — the notice is real, the obligation is real, and both ways out are simple once you know them.

5 min readUpdated 17 July 2026

The short version

What you received
A CT603 'notice to deliver a Company Tax Return' — a legal demand for a CT600 for the stated period, dormant or not.
Your two routes
File a nil CT600 for the period, or get HMRC to withdraw the notice by telling them the company is dormant.
Deadline
12 months after the end of the period the notice covers — and penalties run from the day after, even at zero tax.
If you ignore it
£200 immediately, another £200 at three months (doubled from April 2026), then tax-geared additions — on a company that owes nothing.

What the notice actually is

The letter is a CT603 — notice to deliver a Company Tax Return. It is not a suggestion and it does not care that your company is dormant: once issued, it creates a legal obligation to deliver a CT600 for the period it states. The good news is that the obligation can be satisfied two ways, and both are quick.

Route one: file the nil return

A dormant company's CT600 is a nil return — zeros in the tax boxes, the company's details, and (usually) the dormant accounts attached. Since HMRC's free service closed in March 2026, this has to travel through commercial filing software. Filing the nil return discharges the notice completely, and you keep the acknowledgement as proof.

Route two: get the notice withdrawn

If the company genuinely has had no significant transactions, you can tell HMRC it's dormant — online or by phone — and ask for the notice to be withdrawn. If HMRC agrees, there is nothing to file, and they won't ask again until the company wakes up. Two cautions:

  • Get the withdrawal confirmed. A request that's still in HMRC's queue when the deadline passes does not stop penalties.
  • HMRC's dormancy test is its own thing — bank interest, for example, can make a company active for Corporation Tax even while its Companies House accounts stay dormant.

When the notice covers the wrong dates

A recurring trap: the notice's period doesn't match your accounts. This usually follows a change of accounting reference date — HMRC assumed a 12-month first period and never heard about your change. Don't file a return for a period that isn't yours; call HMRC and have the Corporation Tax periods aligned first. A CT600 for the wrong period doesn't discharge the notice that was issued.

Penalties run even at zero tax

Since April 2026 a late CT600 costs £200 from the first day, another £200 at three months, and up to £1,000 each for repeat offenders — regardless of the fact that a nil return means no tax was ever due. An unanswered notice is the most expensive way to owe nothing.

How WrenTax does it

WrenTax prepares the nil CT600 and dormant accounts from the official register, shows you both documents before you pay, files to HMRC and Companies House, and tracks each register's acknowledgement — £29, one payment. If you'd rather try the withdrawal route first, our dormant accounts guide covers exactly what to say to HMRC. General information, not tax advice.

Common questions

My company is dormant — do I really have to file a tax return?

No — but you can't ignore it either. A notice to deliver creates a legal obligation to file, dormant or not, and the late-filing penalties (£200 from day one since April 2026) apply even when the tax due is zero. Your two routes: file a nil CT600 for the period, or contact HMRC, explain the company is dormant, and ask for the notice to be withdrawn.

How do I get the notice withdrawn?

Tell HMRC the company is dormant using their online service or by phone. If they agree, they withdraw the notice and won't send another until something changes — you then have no CT600 to file. Get the withdrawal confirmed before the filing deadline passes; a request that's still being processed does not stop the penalty clock.

The notice covers the wrong dates — what do I do?

This happens when Companies House and HMRC have different ideas of your accounting period — commonly after you shorten your accounting reference date, because HMRC assumes a first period of 12 months. The fix is to call HMRC and have them align the Corporation Tax period to your real one. A CT600 filed for the wrong period doesn't discharge the notice.

Keep reading

Filing dormant accountsReadFree HMRC service closed: optionsReadCorporation Tax deadlinesRead

This guide is general information about UK company filing, not tax or legal advice. Figures and deadlines are current for 2026; always check your own dates against Companies House and HMRC. Register data © Companies House.