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Reviewed Companies House tool

Dormant Company Filing Deadline Calculator

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

Last reviewed 28 September 2026. Rule basis: Companies House guidance and the cited legislation. Private companies required to file accounts. Registered ARD and valid change facts supplied; no approved extension, public-company or dormant-subsidiary exemption determination.

Dormant Company Filing Deadline Calculator

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

Use the registered ARD, not an accounts made-up date up to seven days either side. Choose the calendar date. Your browser controls the date order; for example, 26 September 2026.

Leave blank for subsequent accounts unless you want the date sequence checked. Choose the calendar date. Your browser controls the date order; for example, 26 September 2026.

Every shortening uses the later of the applicable first/subsequent deadline and actual receipt plus three months. An earlier first ARD needs a valid shortening notice. This tool does not validate whether an AA01 change was legally permitted.

Leave blank unless shortened is selected. Enter receipt of the valid shortening notice, not its posting date. Choose the calendar date. Your browser controls the date order; for example, 26 September 2026.

What this tool answers

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

Private companies required to file accounts. Registered ARD and valid change facts supplied; no approved extension, public-company or dormant-subsidiary exemption determination.

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 result 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.

Turn the result into an action plan

Confirm the dates and status on the Companies House register.

Read the paired guide and primary sources before relying on an exceptional case.

Read the guide

Dormant company filing rules

Read the supported rule, assumptions and worked examples behind this tool.

Assumptions and limits

This tool applies a published rule set directly and is designed for standard scenarios.

Assumptions

  • Private companies required to file accounts. Registered ARD and valid change facts supplied; no approved extension, public-company or dormant-subsidiary exemption determination.
  • The entered facts and registered dates are accurate; this is not a live Companies House lookup.

Limits and rule basis

  • 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.

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.