The Quarter of the UK Register That Trades Nothing: Dormant Companies, AA02 Filings and What ECCTA Now Demands

About one in four companies on the UK register reports no trading activity at all. They file no profit and loss account, employ no one, and in many cases have never invoiced a customer. They are the dormant companies — a category written into the Companies Act 2006 with surgical precision, and a corner of the register that has expanded faster than incorporations as a whole over the last decade.

The dormant population is not a curiosity. It is on the order of 1.3 million entities on a register of about 5.4 million — a population larger than the active limited-company stock of most European jurisdictions. It is also the category most exposed to the Economic Crime and Corporate Transparency Act 2023 (ECCTA), because dormant filings are short, formulaic, and historically have been the easiest place to park a company that exists in name only.

This piece walks through what dormant means in law, what the data actually shows, the legitimate and illegitimate uses of the AA02 filing, and what changes inside the next twelve months as ECCTA's later provisions phase in.

What dormant actually means

The statutory definition sits at section 1169 of the Companies Act 2006. A company is dormant during any period in which it has had no "significant accounting transactions". The Act then carves out four narrow exceptions that do not break dormancy:

• payments for shares taken by subscribers at the moment of incorporation;
• fees paid to the Registrar of Companies (filing fees, late filing penalties, change-of-name fees);
• civil penalties for failure to deliver accounts on time;
• money paid in respect of share capital where the shares were issued on the same terms as the original subscription.

Anything else — a single bank charge, a postage stamp, an inter-company loan repayment, a domain renewal billed to the company — counts as a significant accounting transaction and breaks dormancy for the relevant financial year. The definition is binary, and it is unforgiving.

The practical consequence is that dormancy is a status maintained, not declared. A company is not "registered as dormant" at Companies House. It simply files dormant accounts on the AA02 form (a two-page balance-sheet-only return, available only to companies that have been dormant since incorporation) or, if it has previously traded, files dormant accounts using the standard small-company format with zeroes in the profit and loss columns.

How many dormant companies are there

Companies House does not publish a single headline figure for dormancy. The number has to be reconstructed from the monthly statistical release and the accounts-type tables. The picture for the period running into the 2025–26 financial year is set out below.

Two structural points stand out. First, the dormant population has grown faster than the register as a whole between 2019 and 2024 — accounts type-mix data shows AA02 filings up roughly 35% over five years, against a 14% rise in live companies. Second, AA02 (dormant since incorporation) is the fastest-growing sub-category, indicating that a meaningful share of the register now consists of entities that have never traded and may never trade.

The AA02 form, in plain English

The AA02 is the simplest accounts return Companies House accepts. It contains:

1. The company name and registered number.
2. The financial year covered.
3. A balance sheet showing called-up share capital not paid (usually £1 or £100), the corresponding shareholders' funds, and nothing else.
4. A statement that the company has been dormant throughout the period.
5. Director signatures.

Filing fees are nil. The accounts must be delivered within nine months of the year-end for a private company. Late delivery triggers the same civil penalty bands as any small company — bands that have not been uprated since 2009:

Penalties double if accounts are late two years running. For a dormant company this matters more than people think, because the AA02 is so simple to file that lateness is almost always a signal that the registered office is unattended — which in turn is the strongest predictive indicator the Insolvency Service uses when sifting strike-off candidates.

The legitimate uses of a dormant company

There are six broadly recognised, lawful reasons to maintain a dormant entity on the register. They cover most of the population.

1. Name protection. An incorporator parks a trading name as a limited company to prevent a competitor from registering it. Cheap, effective, entirely legal — though the company is purely defensive.
2. Brand or IP holding. A dormant subsidiary holds a trade mark or domain name on behalf of a trading parent. Inter-company billing must be carefully avoided, or the dormancy breaks.
3. Pre-trading shell. Founders incorporate ahead of investment or launch, often years before the business begins to trade. The AA02 is filed each year while the entity waits for capital.
4. Inactive subsidiaries within a group. Larger groups commonly carry dozens of dormant entities — leftovers from acquisitions, defunct trading arms, legacy partnerships. Maintaining them is cheaper than dissolving and re-registering should they need to be reactivated.
5. Group holding entities. A parent whose only function is to hold shares in subsidiaries can sometimes meet the dormancy test, although group dividends and inter-company loans frequently break it.
6. Shelf companies. Formation agents incorporate companies, never trade them, and sell them to third parties wanting an "aged" entity. The shelf-company market is small but persistent — the premium for an incorporation date older than five years runs at £600 to £1,200.

The fraud question

The characteristics that make dormancy economically efficient also make it attractive to fraudsters. A dormant company has a registered office, a director, a number and a clean filing record. It can open a bank account, apply for VAT registration and bid for procurement contracts. It looks identical to a genuinely pre-trading shell until the day it issues its first invoice — and that invoice may be the only one it ever issues.

The Insolvency Service's disqualification statistics show that AA02-filing entities accounted for an outsized share of bounce back loan disqualifications between 2022 and 2024, despite being a minority of the loan book. Dormant subsidiaries inside complex group structures have featured in several of the largest VAT carousel cases prosecuted by HMRC over the same period.

ECCTA addresses this in three ways, all of which have either commenced or are commencing inside 2026:

• Identity verification of directors and PSCs. Mandatory rolling out from spring 2026 through to spring 2027. Every director of a dormant company must verify their identity through an Authorised Corporate Service Provider (ACSP) or directly through Companies House.
• The lawful purpose statement. Live since 4 March 2024. On incorporation and at each confirmation statement, the company must affirm that it is being formed for lawful purposes. A company that incorporates, files AA02 every year and never trades is not in itself suspicious — but a serial incorporator filing dozens of dormant returns from a single residential registered office now triggers the registrar's new section 1075 query power.
• Registrar's own-motion strike-off. Under the new powers inserted by ECCTA, the registrar can strike off a company believed on reasonable grounds to be used for a fraudulent purpose, without going through the full two-month gazette process.

The combined effect is that dormant filings are no longer the lowest-friction part of the register. They are now the part most actively scrutinised.

The dormant-subsidiary route

A dormant subsidiary inside a group has historically enjoyed two further reliefs that warrant their own line. Section 394A allows a dormant subsidiary to take an exemption from preparing individual accounts altogether, provided the parent guarantees its liabilities under section 479A and includes the subsidiary in audited group accounts. The combined effect: no individual accounts at all, only a parent guarantee on the file.

Take-up of section 394A is concentrated in the largest groups. Of the FTSE 100, the majority have at least one section 394A subsidiary; a typical FTSE 350 group reports between three and nine. ECCTA does not change section 394A directly, but the broader move under the small-companies regime to require profit and loss accounts from previously filleting micros will shift attention back onto whether the parent guarantee is being used appropriately. Expect the registrar's compliance team to issue more queries in the second half of 2026 on whether named subsidiaries actually meet the section 1169 dormancy test, rather than merely qualifying for the s394A relief.

The next twelve months

Three regulatory events will reshape the dormant-company economy by mid-2027:

1. Mandatory identity verification of every director, including dormant-company directors, by April 2027.
2. Companies House's continuing rejection of AA02 filings from registered offices flagged as non-bona-fide under the "appropriate address" power introduced by ECCTA.
3. The eventual transition of all accounts filing to software-only channels, removing the WebFiling AA02 option and forcing dormant companies onto commercial software or a third-party agent.

None of these changes bans dormant companies, and none of them are intended to. They make the cost of maintaining one — in identity verification effort, in registered-office discipline, in software subscription — measurably higher than it has been since the modern register was assembled in the 1990s. The likely outcome is that the dormant population peaks around 2027, then declines for the first time on record as the cost of inactive existence finally outpaces the £34 annual confirmation-statement fee.

For anyone using Company Record to triage UK counterparties, the practical implication is simpler still: a clean run of AA02 filings is no longer evidence of nothing. It is, increasingly, evidence of a deliberate choice — and one the registrar is now equipped to question.