Form AA06: How to File a Statement of Guarantee at Companies House

At a glance

• What it is: a statement of guarantee, filed at Companies House by a parent undertaking, guaranteeing a UK subsidiary's outstanding liabilities.
• Three uses, one form: the current AA06 form covers three separate exemptions — preparing individual accounts for a dormant subsidiary (section 394C), filing accounts for a dormant subsidiary (section 448C), and the audit exemption for an active subsidiary (section 479C).
• What the guarantee covers: all of the subsidiary's outstanding liabilities as at the relevant financial year end, until they are satisfied in full — this wording is identical across all three routes.
• Who signs: both a director of the subsidiary company and a representative of the parent undertaking must sign the form, in separate sections.
• Parent eligibility: the parent undertaking must be established under the law of a part of the United Kingdom. Since 31 December 2020, an EEA-incorporated parent no longer automatically qualifies.
• Deadline: the AA06 and its supporting documents must reach Companies House on or before the date the subsidiary's own accounts are due — 9 months after the financial year end for a private company, 6 months for a public company, under section 442.
• Not rolling: a fresh AA06 is needed for each financial year the exemption is claimed.
• Not for LLPs: a subsidiary that is a limited liability partnership needs form LLAA06 instead of AA06.

What form AA06 is for

AA06 is titled "statement of guarantee by a parent undertaking of a subsidiary company." On its face it is a short, three-page form. What it actually does depends entirely on which box you tick, because Companies House uses the same form and the same guarantee mechanism for three different purposes:

| Route | Statutory basis | What it exempts | Subsidiary must be | |---|---|---|---| | Dormant subsidiary — accounts preparation | Section 394C, conditions in section 394A | The subsidiary does not have to prepare individual accounts for the year | Dormant throughout the financial year | | Dormant subsidiary — accounts filing | Section 448C, conditions in section 448A | The subsidiary does not have to deliver a copy of its individual accounts to the registrar | Dormant throughout the financial year | | Audit exemption for a subsidiary | Section 479C, conditions in section 479A | The subsidiary's individual accounts do not need to be audited | Trading normally — this route does not require dormancy |

The first two routes exist for a genuinely dormant subsidiary — one with "no significant accounting transaction" in the financial year, within the meaning of section 1169. The third route is the one most people mean when they talk about "the AA06 audit exemption," and it is available to a trading subsidiary, not just a dormant one. These are three distinct legal outcomes, not three names for the same thing, so identify which one you actually need before you complete the form.

What the guarantee actually commits the parent to

Whichever route applies, the guarantee mechanism is identical. Under section 479C(3) (and the equivalent provisions at section 394C(3) and section 448C(3)):

the parent undertaking guarantees all outstanding liabilities to which the subsidiary company is subject at the end of the financial year to which the guarantee relates, until they are satisfied in full, and the guarantee is enforceable against the parent undertaking by any person to whom the subsidiary company is liable in respect of those liabilities.

Two things follow from that wording. First, the guarantee is tied to a single financial year — it is not an open-ended guarantee of the subsidiary's future trading debts. Second, it is enforceable directly by the subsidiary's creditors against the parent, not just a private arrangement between the two companies. Once the statement is delivered to the registrar, this is a real legal commitment, not paperwork.

Which route applies to you

Dormant subsidiary exemptions (sections 394A/394C and 448A/448C)

Both dormant-subsidiary routes require the subsidiary to have been dormant throughout the whole of the financial year, its parent undertaking to be established under UK law, all members of the subsidiary to agree to the exemption for that year, and the subsidiary to be included in the parent's consolidated accounts, with the parent disclosing the exemption in the notes to those accounts. The accounts-preparation exemption (394A/394C) means the subsidiary need not draw up its own individual accounts at all; the filing exemption (448A/448C) means it can prepare them but does not have to deliver a copy to the registrar. Groups sometimes need only one of these, so check the wording on the form carefully.

Audit exemption for a subsidiary (section 479A/479C)

This route is available to a company that is a subsidiary undertaking with a parent established under UK law, provided all members agree to the exemption, the parent gives the guarantee under section 479C, and the subsidiary is included in the parent's consolidated accounts with the exemption disclosed in the notes. Unlike the dormant-subsidiary routes, the subsidiary can be actively trading. Section 479B excludes certain companies from this route regardless of the guarantee — including traded companies, authorised insurers, banking companies, e-money issuers, MiFID investment firms, UCITS management companies, and certain pension scheme funders and trade union or employers' association bodies. If your subsidiary falls into one of these categories, the section 479A/479C route is not open to it.

How to complete the AA06 form

The current AA06 form (Companies House form AA06) is structured in numbered sections:

1. Subsidiary company details. The full registered name and company number of the subsidiary claiming the exemption, exactly as they appear on the public register.
2. Relevant financial year. The date the subsidiary's financial year ends, to which the guarantee relates.
3. Guarantee. Details of the guarantee, including which section of the Companies Act 2006 it is given under (394C, 448C or 479C), and the name and registered number of the parent undertaking giving it.
4. Statement date. The date the statement itself was made.
5. Signature on behalf of the parent undertaking. This section authenticates the guarantee and must be signed by someone with authority to bind the parent.
6. Signature of subsidiary. A director of the subsidiary company must also sign, because it is the subsidiary's directors who deliver the statement to the registrar.

An optional presenter information section lets you leave contact details in case Companies House has a query, though this is not mandatory. Everything entered on the form becomes part of the public record, so double-check company names and numbers against the register before you file — mismatches are a common reason forms are returned.

What else you must file alongside it

The AA06 on its own is not enough for any of the three routes. By the date the subsidiary's accounts are due, its directors must also deliver:

• A written notice that all members of the subsidiary agree to the exemption for that financial year.
• A copy of the parent undertaking's consolidated accounts for the relevant period (or an earlier date in that year).
• A copy of the auditor's report on those consolidated accounts.
• A copy of the parent's consolidated annual report.

Missing any one of these can invalidate the exemption, even where the AA06 itself was completed correctly and filed on time.

Filing deadline and what happens if you're late

The AA06 and the supporting documents must reach Companies House on or before the date the subsidiary's own accounts and reports are due for that financial year. Under section 442, that is normally 9 months after the end of the accounting reference period for a private company and 6 months for a public company.

There are two separate consequences of missing that date. First, the exemption itself falls away for that financial year — for the audit-exemption route, this can mean the subsidiary's accounts need a full audit after all; for the dormant-subsidiary routes, it can mean the subsidiary must prepare and/or file its own individual accounts. Second, filing the subsidiary's accounts late in their own right can trigger a civil penalty under section 453 of the Companies Act 2006, banded by how late the accounts are and whether the company is public or private — check GOV.UK for the current penalty tables, as these are set by separate regulations rather than the Act itself.

Worked example

Riverside Holdings Ltd owns Riverside Trading Ltd, an active subsidiary. Riverside Trading's financial year ends on 31 March. Riverside Holdings, as parent, agrees to guarantee Riverside Trading's liabilities for that year so that Riverside Trading can rely on the audit exemption under section 479A/479C.

Before Riverside Trading's accounts are due — 9 months later, on 31 December — the directors must have delivered to Companies House: the written notice that all of Riverside Trading's members agree to the exemption; the AA06 statement of guarantee, signed by an authorised person at Riverside Holdings and by a Riverside Trading director; a copy of Riverside Holdings' consolidated accounts for the year, including the auditor's report and the consolidated annual report; and Riverside Trading's own (unaudited) accounts, with the exemption disclosed in Riverside Holdings' notes.

If Riverside Trading wants to rely on the same exemption the following year, Riverside Holdings must give a fresh guarantee for that year — the AA06 filed for the year ending 31 March does not carry forward automatically.

Common mistakes that undermine the exemption

• Treating one AA06 as covering multiple years. The guarantee is tied to a specific financial year; a new statement is needed each year the exemption is claimed.
• Filing the AA06 but missing a supporting document. The written members' notice, the parent's consolidated accounts, the auditor's report and the consolidated annual report are all separate requirements — the exemption depends on all of them arriving on time, not just the AA06.
• Assuming an overseas parent qualifies. Since 31 December 2020, the parent undertaking must be established under UK law. A parent incorporated elsewhere in the EEA no longer automatically qualifies, even though it did before that date.
• Only one party signing. The current form requires both a subsidiary director's signature and a signature on behalf of the parent — a form signed by only one side is incomplete.
• Confusing the three routes. Using the form for the audit exemption when what you actually needed was the dormant-subsidiary filing exemption (or vice versa) means the wrong box gets ticked and the wrong conditions apply.

What to do next

1. Identify which of the three exemptions you actually need — dormant-subsidiary accounts preparation, dormant-subsidiary filing, or the audit exemption for a trading subsidiary.
2. Check the parent qualifies. Confirm it is established under UK law and is willing to accept a real, enforceable guarantee over the subsidiary's liabilities at the relevant year end.
3. Confirm the subsidiary isn't excluded. For the audit-exemption route in particular, check the subsidiary doesn't fall within one of the excluded categories in section 479B.
4. Gather the supporting documents early — the members' written agreement, the parent's consolidated accounts, the auditor's report and the consolidated annual report all need to be ready alongside the AA06.
5. Get both signatures. Arrange for an authorised person at the parent and a director of the subsidiary to sign the form.
6. File everything by the subsidiary's accounts deadline — 9 months (private) or 6 months (public) after the financial year end — and keep evidence of when it was delivered.
7. Take advice early if your group structure is unusual — an overseas parent, a recently changed group structure, or a subsidiary close to one of the excluded categories are all situations where a short conversation before you sign can save an invalidated exemption later.

This guide provides general information about form AA06 and the exemptions it supports under the Companies Act 2006. It is not legal advice and is not a substitute for advice tailored to your specific group structure. The law described was accurate as at August 2026 and is subject to change — always check GOV.UK and legislation.gov.uk for the most current position.

Last reviewed: August 2026 by a non-practising solicitor · Next review due: August 2027 or on legislative change.