Shaping the Future of AIM: What the New AIM Rules Mean for Growth Companies, Founders and Advisers

AIM has undergone its most significant regulatory overhaul in years, and market participants should take note.

On 4 June 2026, the London Stock Exchange published AIM Notice 62, launching a wide-ranging consultation on proposed amendments to the AIM Rules for Companies under its “Shaping the Future of AIM” programme. Following that consultation, the London Stock Exchange confirmed the final amendments in AIM Notice 64, and the revised AIM Rules for Companies took effect on 5 August 2026. The direction of travel is unmistakable: a lighter, more proportionate regime designed to make AIM more competitive and more attractive to growth and founder-led businesses.

In practical terms, the reforms are about reducing friction at IPO and giving companies greater flexibility once on market.

These reforms build on a sustained period of market engagement, beginning with the April 2025 discussion paper and followed by the November 2025 Feedback Statement, which confirmed broad support for many of the changes. A number of these measures were already being applied in practice and have now been formalised into the AIM Rules, a welcome step towards greater certainty for issuers, their nominated advisers and other market participants.

A Leaner Admissions Process

One of the most significant changes is the overhaul of the admissions framework. The Exchange recognised that the AIM admission document had become increasingly complex and resource-intensive and, in some cases, a barrier to entry.

Most notably, the directors’ working capital statement, historically a significant cost driver, has been removed and replaced with a disclosure-based regime. Applicants must instead disclose details of their material capital resources, material financial commitments, obligations liabilities, the intended use of admission proceeds and the directors’ reasonable opinion on anticipated funding needs over the next twelve months.  However, it remains to be seen whether nominated advisers will still require a full working capital exercise to be undertaken as part of the diligence process in order to satisfy themselves as to suitability.

UK-incorporated AIM companies can also now use UK GAAP (FRS 102) instead of IFRS, potentially saving significant time and cost by avoiding a full IFRS conversion. A policy approach that had already been applied in practice and is now formalised in the rules. The Exchange has confirmed that it will continue to consider other local accounting standards on a case-by-case basis where equivalence to IFRS can be demonstrated.  Similarly with the working capital statement, how nominated advisers and brokers approach the new regime will take some time to play out.  Some institutional investors may well still want the comfort of IFRS numbers.

The new rules also permit information to be incorporated by reference into an admission document, provided the applicant, supported by its nominated adviser, is satisfied that this is appropriate.

Taken together, these changes should materially reduce the cost and complexity of coming to market on AIM.

Facilitating Fundraisings and Transactions

The final rules also introduce a Capital Access Window, a new voluntary mechanism allowing companies to request a temporary suspension of trading while conducting an equity fundraise or other corporate transaction.

This is intended to support the execution of fundraisings and facilitate broader investor participation, addressing some of the practical challenges companies face in live transactions. Requests will be considered by the Exchange, via the company’s nominated adviser, on a case-by-case basis.

At the same time, the threshold for substantial transactions has increased from 10% to 25%, aligning AIM with the Main Market and reducing the regulatory burden on companies undertaking acquisitions and disposals in the ordinary course of business.

The final rules also remove the profits test from the substantial transaction regime, although the Exchange has confirmed that it will be retained for the purpose of assessing related party transactions.

The rules on reverse takeovers have also been refined: exceeding 100% in the class tests will no longer, of itself, result in a transaction being classified as a reverse takeover, provided there is no fundamental change to the company’s business, board or voting control. The Exchange has also formalised its practice of not suspending trading in an AIM company’s shares where a reverse takeover is in contemplation, provided the nominated adviser is satisfied that appropriate alternative disclosure can be made.

New Routes to AIM

The new rules also open up new pathways for companies seeking an AIM listing.

An Express Market Route has replaced the former Designated Market Route, broadening access for international issuers admitted to markets which are members of the International Organisation of Securities Commissions. A new dual market admission route has also been introduced, including for Main Market applicants and for companies admitting simultaneously to an Express Market alongside an independent equity fundraise of at least £6 million.

These changes underline a clear ambition to position AIM as a more internationally competitive growth market.

Supporting Founder-Led Businesses

A particularly welcome theme is the continued focus on founder-led and innovative companies.

The final rules provide greater flexibility around capital structures, governance and remuneration arrangements, including the codification of the ability to offer dual-class or special voting share structures at IPO, drawing on the Main Market’s experience in this area.

This recognises the reality that founders often want to retain meaningful control post-listing, and that enabling them to do so can be a key factor in attracting high-quality companies to public markets.

Modernising Corporate Governance and Disclosure

The final rules also overhaul AIM’s corporate governance and disclosure framework. The former “comply or explain” approach under AIM Rule 26 has been replaced: AIM companies must still have regard to a recognised corporate governance code, such as the QCA Code, but are no longer required to report formally against it. Instead, companies must disclose their approach across five prescribed areas: board composition, directors’ roles and responsibilities, remuneration and performance, risk and controls framework, and investor relations and shareholder engagement.

The general disclosure obligation in AIM Rule 11 has also been replaced, with a new rule focused on the procedures an AIM company has in place to identify developments that may affect its business or prospects, and on its engagement with its nominated adviser on such matters.

Buyer Beware Reinforced

Underpinning these reforms is a reinforcement of AIM’s longstanding “buyer beware” model.

Clear buyer-beware language is now embedded directly in the AIM Rules, including a prominent disclosure on the front page of every admission document. This sits alongside the broader shift to a more disclosure-led, proportionate regime, placing appropriate emphasis on investor judgement.

Where This Leaves Market Participants

The revised AIM Rules for Companies, together with corresponding changes to the AIM Rules for Nominated Advisers, took effect on 5 August 2026, confirmed by the Exchange in AIM Notice 64 and AIM Notice 65 respectively, largely as consulted on with some minor amendments.

For AIM companies, nominated advisers and investors alike, these reforms represent a meaningful recalibration of AIM’s regulatory framework, one aimed at ensuring the market remains competitive, flexible and attractive to growth companies.

Whether you are planning a fundraise or assessing the market more broadly, we can help you to understand the impact of these changes.