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Filing deadline tool

Accounts Filing Deadline Calculator

Calculate the filing deadline for a UK private company, public company or LLP from its registered ARD, first-accounts facts and any valid shortening notice.

Last reviewed 28 September 2026. Companies House guidance and Companies Act 2006 sections 442–443. Standard and valid changed periods only; approved extensions, uncertain changes and leap-day incorporation require review.

Accounts Filing Deadline Calculator

Calculate the Companies House deadline for normal, first or valid shortened accounts periods using registered dates and the applicable filing rule.

Company type

Use the entity type immediately before the reference period ended. Re-registration or uncertainty requires review.

Which filing are you calculating?

Required for first accounts. For later accounts, leave blank or supply it for date-sequence validation only. Choose the calendar date. Your browser controls the date order; for example, 26 September 2026.

Copy the registered ARD from Companies House, not a nearby accounts made-up date (which can differ by up to seven days). Choose the calendar date. Your browser controls the date order; for example, 26 September 2026.

A shortening uses the later applicable deadline, including three months from actual receipt of the valid notice. The tool does not establish whether an ARD change was legally permitted.

Required only when shortened is selected. Use Companies House's actual receipt of the valid AA01 notice, not the date it was posted. If unknown, confirm the registered deadline instead. Choose the calendar date. Your browser controls the date order; for example, 26 September 2026.

What this deadline calculation covers

The result applies the Companies House filing rule to accurate registered dates for normal, first or already-valid changed periods. Dormancy alone does not change the deadline.

First accounts need incorporation and the registered ARD. An ARD earlier than the normal first reference date indicates shortening: without a known valid notice receipt, the result is review required, not a guessed date.

Rule summary

Standard annual accounts filing windows

Private companies and LLPs normally file annual accounts 9 months after the accounting reference date. Public companies normally file within 6 months.

A month-end registered ARD produces a month-end deadline: 30 April 2026 plus nine accounts-calendar months is 31 January 2027, not 30 January. Non-month-end dates retain the corresponding day, clamped to February month-end where necessary.

First reference periods count incorporation as day one. For periods over 12 months, use the later of nine months (private/LLP) or six months (public) from the first incorporation anniversary and three months from the ARD; normally 21 or 18 months from incorporation. Periods of 12 months or less use the ordinary window.

Section 443 applies month-end handling to specified dates used in accounts filing periods. Generic tax and penalty date arithmetic is unchanged.

For a valid shortened period, section 442(4) selects the later of the applicable underlying deadline and three months from actual receipt of the notice. If the shortened first period still exceeds 12 months, retain the long-first-period rule rather than replacing it with ARD plus nine or six months.

A valid lengthening uses the new registered ARD and the same applicable first/subsequent rule; lengthening is not an approved extension of time to file. Weekends and bank holidays do not extend filing deadlines.

Standard filing windows used here

Private companies and LLPs normally file annual accounts 9 months after the accounting reference date. Public companies normally file within 6 months.

For first accounts, a longer incorporation-based rule can matter when the first accounting period is longer than 12 months.

Worked examples

How the result behaves in practice

Corresponding day, not a fixed day count

Later private company accounts with registered ARD 4 April 2026.

Deadline 4 January 2027, not 31 January: this ARD is not a month-end date.

Later private company accounts

Later private company accounts with registered ARD 30 April 2026.

Deadline 31 January 2027: a month-end ARD gives a month-end filing deadline.

First accounts with a longer opening period

Private company incorporated 1 January 2025, first ARD 31 January 2026.

Later of 1 October 2026 and 30 April 2026: deadline 1 October 2026. This is the Companies House first-accounts example.

Shortened first period: receipt-based deadline wins

Private company incorporated 1 January 2025; valid shortened first ARD 31 December 2025; Companies House received the notice on 31 August 2026, before the old 1 October 2026 deadline.

Underlying 12-month period deadline: 30 September 2026. Notice receipt plus three accounts-calendar months: 30 November 2026. Select the later date: 30 November 2026. Without the receipt fact, review is required.

Turn the result into an action plan

Check whether the accounting reference date and filing cycle have been identified correctly before you rely on the date.

If the deadline is close or already passed, use the Companies House late filing penalty tool; do not confuse accounts filing with CT600 or Corporation Tax payment.

Keep the date in a wider compliance calendar so the filing does not become an isolated one-off check.

Read the guide

Accounts filing deadlines

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

  • The company type and filing cycle are selected correctly.
  • The accounting reference date is the date that governs the filing window.
  • Any ARD change is already legally valid and registered. Shortening notices were received before the old filing deadline; their actual receipt date is known.

Limits and rule basis

  • Approved filing extensions, disputed changes, leap-day incorporation, first periods over 18 months, overseas companies, re-registration, insolvency and historic transitional cases require review.
  • This is not an ARD-change eligibility check or live register lookup. Subsequent period length/previous ARD and dormant-subsidiary filing exemptions are not established; confirm those facts separately.

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 Act accounts filing rules, including sections 442–443.

Reviewed scope: Private companies and LLPs; supported first/later accounts and valid changes; extensions and uncertain facts require review.

Review basis and change triggers

Reviewed model: accounts-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

Why does the tool ask for the incorporation date?

It is needed for first accounts because the filing deadline can depend on the incorporation-based statutory deadline as well as the accounting reference date.