UK: London Stock Exchange confirms AIM Rule changes

Why should I read this?

On 5 August 2026, the London Stock Exchange (Exchange) published AIM Notice 64, setting out feedback on the June 2026 consultation on proposed changes to the AIM Rules for Companies (AIM Rules), and confirmed implementation of the changes.

The rule changes took effect immediately and are intended to enhance AIM's attractiveness as a market for growth companies, reduce regulatory friction and streamline capital raising and M&A activity. The Exchange indicates that there was strong support for most of the proposed changes.

The final rules largely reflect the June consultation proposals, which we commented on in our briefing: Proposed changes to the AIM Rules. However, the Exchange has made targeted amendments in response to market feedback and regulatory considerations.

Key changes

Admission documents

The Exchange confirms the removal of the traditional working capital statement from AIM admission documents. Instead, applicants must disclose their material capital resources, material financial commitments and liabilities, use of admission proceeds and the directors' reasonable opinion on future fundraising needs over the next 12 months.

The final rules also permit information to be incorporated by reference, provided it remains publicly available for the period during which the admission document must remain available. Together, these reforms are intended to reduce the cost and complexity of preparing AIM admission documents.

Permitted accounting standards

UK and EEA incorporated AIM companies may now prepare their accounts using local GAAP rather than IFRS. For UK issuers, UK GAAP (FRS 102) is now expressly permitted. 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.

New Capital Access Window

A new Capital Access Window allows AIM companies to request a temporary suspension while negotiating an equity fundraising or transaction involving the issue of AIM securities. The Exchange expects these periods to be short and will consider requests on a case-by-case basis. AIM companies must notify entry into the window and, on exit, make a “cleansing notification” confirming that the fundraise or transaction has completed or aborted. AIM companies remain subject to the AIM Rules and UK MAR throughout.

M&A activity

The final rules confirm several changes to the AIM substantial transaction regime:

• the threshold for a substantial transaction increases from 10% to 25% (to align with the Main Market);
• the profits test is removed from the substantial transaction regime;
• the Exchange confirms that the profits test remains an important indicator for related party transactions and will be retained for that purpose;
• investing companies may pro-rate the gross capital test in certain circumstances; and
• class test results may be disregarded where both numerator and denominator are zero.

Reverse takeovers

Acquisitions exceeding 100% in  any of the class tests are no longer automatically treated as reverse takeovers. Under revised AIM Rule 14, a reverse takeover is now defined as an acquisition by an AIM company that would “result in a fundamental change in its business, board or voting control” or, for investing companies, would “depart materially from its investing policy”. The reference to exceeding 100% in the class tests has been moved to the guidance as a factor to consider when assessing whether a fundamental change has occurred. The Exchange did not consider it necessary to define “fundamental change” further, noting that the guidance to Rule 14 allows each transaction to be considered on its facts.

The rules also clarify the position where a transaction exceeds 100% in any of the class tests but does not result in a fundamental change of business, board or voting control. The guidance to Rule 12  (Substantial transactions) provides for consultation with the Exchange if the company does not propose to seek shareholder approval, with the Exchange considering matters case by case with the nominated adviser (Nomad).

The Exchange has also formalised its policy of not suspending trading in an AIM company’s shares where a reverse takeover is in contemplation, provided the Nomad is satisfied that appropriate alternative disclosure can be made.

Related party transactions and director remuneration

The Exchange notes respondent support for removing the requirement for the Nomad to provide a fair and reasonable opinion on non-standard director remuneration where they are satisfied that contractual terms provide reasonable commercial protections.

The guidance to Rule 13 (related party transactions) now provides that:

• Non-standard director remuneration will be treated as a related party transaction. However, a fair and reasonableness opinion from a Nomad will not be required where the Nomad is satisfied that the contractual terms provide reasonable commercial protections. Where there is uncertainty, the matter should be put to a shareholder vote.
• The requirements of AIM Rule 13 continue to apply to non-standard director remuneration, including a fair and reasonableness statement from the independent directors. Where there are no independent directors, a shareholder vote may be required.

Guidance has also been added on what constitutes standard remuneration (which will not be considered a related party transaction).

The Exchange has removed PDMRs from the definition of “related party” following feedback that including PDMRs risked creating a broader regime than applies on the Main Market.

Special voting shares permitted

The reforms permit specified parties to hold special voting shares at admission, allowing founder-led businesses to adopt dual-class structures on AIM. Constitutional safeguards are required, including transfer restrictions and limits on voting rights on specified matters. The Exchange decided not to introduce mandatory sunset provisions.

Corporate governance

Rule changes have been made in line with the consultation. The existing AIM Rule 26 “comply or explain” framework has been replaced. Companies should continue to consider a recognised corporate governance code (eg the QCA Code) but are no longer required to report against it. Instead, AIM companies must disclose their corporate governance approach across five prescribed areas considered key to investors:

• board composition;
• directors' roles and responsibilities;
• remuneration and performance;
• risk and controls framework; and
• investor relations and shareholder engagement.

As set out in the consultation, the reforms also introduce voluntary disclosure frameworks on engagement with proxy advisers and company responses to third-party commentary, noting that:

• Proxy adviser engagement disclosure is voluntary and may be made by notification or on the company's website
• The Exchange has stated that a decision not to respond to third-party commentary “should not be interpreted negatively or construed as acceptance”.

AIM Rule 11 replaced

In line with the consultation, the existing AIM Rule 11 disclosure obligation has been removed and replaced with a new rule focused on AIM companies’ procedures for identifying developments that may affect their business or prospects and on engagement with their nominated adviser. The Exchange has confirmed that UK MAR remains the primary disclosure framework for AIM companies.

Express Market route for international companies

The consultation proposed a new Express Market admission route for international applicants. The final rules make some changes to its scope, intended to preserve the route’s policy objective.

Nominated adviser rules

Separately, the Exchange issued AIM Notice 65, confirming changes to the AIM Rules for Nominated Advisers, which were also published for consultation in June. The rules were adopted without further changes to those set out in the consultation.

What’s next?

The rule changes entered into force immediately on 5 August. Taken together, the reforms represent the most significant package of AIM Rule changes for several years, affecting companies considering an AIM IPO, existing AIM issuers planning transactions or fundraisings, and advisers to AIM companies.

A mark-up of the AIM Rules showing the changes, including further changes made to the consultation draft, can be downloaded from the London Stock Exchange website (AIM Notices).