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Dormant company filing rules

Use this guide to separate dormant-company status from the still-important question of when dormant accounts are actually due.

Dormant does not mean date-free

Dormant companies still have filing deadlines. The dormant label changes the nature of the filing, not the need to control the date.

In standard cases the timing follows the usual filing window for the company type and filing cycle.

Rule summary

Rules and how this is calculated

Dormancy affects accounts content, not the standard filing window. Companies House dormancy is separate from Corporation Tax dormancy. A dormant subsidiary may have a specific filing exemption that this tool does not establish.

Subsequent private-company accounts normally have nine months from the ARD. Where the ARD is the last day of a month, the deadline is the last day of the appropriate filing month.

First accounts covering more than 12 months use the later of nine accounts-calendar months from the first incorporation anniversary (normally 21 months from incorporation) and three accounts-calendar months from the ARD. First accounts of 12 months or less use the normal window.

For a valid shortening notice, use the later of the applicable first/subsequent deadline and three accounts-calendar months from Companies House's actual receipt of AA01 (sections 442(4) and 443). Keep the long-first-period rule if the shortened period still exceeds 12 months. An ARD earlier than the normal first reference date requires the valid notice receipt fact. Leap-day incorporation, first periods over 18 months, invalid changes and approved extensions require review.

Worked examples

How the rule behaves in practice

  • Long first accounts: Private company incorporated 1 January 2025, first ARD 31 January 2026. Later of 1 October 2026 and 30 April 2026: deadline 1 October 2026.
  • Month-end and shortening: Later ARD 30 April 2026, standard window; alternatively a valid shortening notice received 15 December 2026. Standard deadline 31 January 2027. With that valid shortening receipt, the later three-month date is 15 March 2027.

Practical consequences

  • Dormant companies often miss dates precisely because teams assume that inactivity means low urgency.
  • Once the filing is missed, the company can still move into the same late-filing and catch-up workflow as an active company.

Important limits

  • Professional review is required for exclusions, disputed dates and facts outside the supported case. No enforcement outcome is predicted.

Primary sources and review date

Reviewed on . Preserved source review from the accepted scoped statutory repair; this contract migration does not re-date that review.

Applies to: Current Companies House accounts rules; dormancy does not remove the normal filing obligation.

Reviewed scope: Private dormant companies required to file; no dormant-subsidiary exemption determination or approved extension.

Review basis and change triggers

Reviewed model: dormant-company-filing-deadline-calculator: companies-house-accounts-reviewed-28 September 2026

  • A cited source or statutory regime changes.
  • Reviewed content, runtime adapter or domain implementation changes.
  • A new effective period falls outside the supported scope.

Turn the result into an action plan

  • Confirm whether the filing is the first set of accounts or a later cycle.
  • Use the deadline calculator to anchor the working date.
  • Keep the dormant filing date in the same calendar as the confirmation statement and tax obligations.

Use the tool

Dormant Company Filing Deadline Calculator

Calculate a private dormant company's accounts filing deadline, distinguishing first accounts and valid shortened periods.

FAQ

Does this tool confirm Companies House's actual recorded position?

No. It calculates or interprets the facts you supply; confirm the register, Gazette or professional advice where required.