The London Stock Exchange has implemented significant reforms to the AIM Rules for Companies and the AIM Rules for Nominated Advisers (AIM Rules), following consultations earlier in 2026 (see our post on the previous consultation here). The majority of the reforms consulted on have been adopted and the reforms, which became effective on 5 August 2026, represent the most comprehensive changes to the AIM Rules since the AIM market was launched in 1995.

Published: 14 August 2026
Authors: Oliver Pilkington

The changes reposition AIM following changes to the UK Listing Rules implemented in July 2024 which had rendered the rules applicable to AIM companies similar, and in some areas more stringent than, those applicable to Main Market companies. The changes are intended to reduce regulatory burdens, improve access to capital and make AIM more attractive to founder-led and growth companies. The key changes are summarised below.

1. Admission process simplified

Working capital statements abolished

The requirement for an admission document to contain a formal working capital statement has been removed. Instead, issuers must provide disclosure regarding their capital resources, financial commitments and obligations, the use of proceeds of any fundraising undertaken on admission, and expected funding requirements over the 12 months following admission. Responsibility for assessing the company's financial position remains with the company and its directors.

Incorporation by reference permitted

Admission documents may now incorporate publicly available information by reference, which should help to reduce document length and duplication. Hyperlinks to the relevant information must be included in the admission document and such information must remain publicly available for as long as the admission document itself is required to remain available under AIM Rule 26.

Accounting flexibility

AIM applicants incorporated in the UK or EEA may now prepare and present their accounts in either IFRS or local GAAP. This is intended to avoid the need for accounts to be restated under IFRS in connection with an AIM admission which can add significantly to transaction costs and affect timing.

2. Capital access windows

AIM companies conducting an equity fundraising or other transaction involving the issue of AIM securities may request a temporary suspension of trading referred to as a "capital access window". The purpose of the capital access window is to give issuers a controlled environment to manage negotiations, reduce execution risk, and prevent market volatility or price shifts from derailing capital raises.

The Exchange has deliberately avoided prescribing minimum or maximum periods and will consider requests on a case-by-case basis. Companies remain subject to UK Market Abuse Regulation (MAR) and AIM Rules obligations during the suspension period.

3. Transaction rules modernised

Reverse takeovers narrowed

A transaction will only constitute a reverse takeover if it results in a fundamental change to the company's business, board or voting control. Exceeding 100% under any of the class tests is no longer, of itself, determinative. Instead, the Exchange expects consultation where the transaction exceeds 100%, is not a fundamental change and shareholder approval is not being sought. Decisions will be made on a case-by-case basis.

Substantial transaction threshold increased

The threshold for a substantial transaction has increased from 10% to 25%, aligning AIM with the UK Listing Rules.

Related party transactions

Participation in a fundraising by directors or substantial shareholders will no longer constitute a related party transaction provided (i) they participate on the same terms as other investors and (ii) the price is set either by directors not participating in the fundraising or by agreement with investors who are not related parties.

The definition of related party has been expanded to include: (i) any company one or more of whose directors is also a director of the AIM company; and (ii) any person with a 10% interest (or more) in an AIM company's subsidiaries and/or assets.

Nominated advisers are no longer required to provide a "fair and reasonable" opinion on non-standard remuneration arrangements where they are satisfied reasonable commercial protections exist for the AIM company and such protections are disclosed. Guidance has been added on what constitutes ‘standard’ and ‘non-standard’ remuneration and provides that, where a nominated adviser is not satisfied that reasonable commercial protections are in place, shareholder approval of any non-standard remuneration should be sought.

4. Ongoing Developments

Rule 11, which previously required general disclosure of price sensitive information, has been replaced with a new ‘Ongoing Developments’ rule which makes it clear that the disclosure regime under the AIM Rules is not intended to conflict with the disclosure regime under MAR. The new Rule 11 specifies that an AIM company must have in place procedures enabling it to monitor and identify any changes that may have a material impact on its business, must keep its nominated adviser updated regarding any such changes and have due regard to the views of its nominated adviser when considering its disclosure obligations under MAR.

The guidance to Rule 11 states that, when providing any view regarding market impact, a nominated adviser is undertaking its obligations to the London Stock Exchange and its view should therefore be considered authoritative. The guidance also provides that, where a nominated adviser considers that a change or development is likely to have a market impact but the AIM company decides not to notify the information without delay (and there is no basis to delay under article 17(4) of MAR) the AIM company and/or its nominated adviser must notify the Exchange immediately and provide the rationale.

5. Special voting shares permitted

AIM will now permit special voting shares at admission, allowing founders, management teams and pre-IPO investors to retain enhanced control rights. Enhanced voting rights may not be exercised in relation to (i) remuneration, (ii) related party transactions involving the holders of such shares or (iii) cancellation of admission.

Special voting shares cannot be issued, nor can the rights attached to them be extended, at any time after admission. A holder of shares with special voting rights may not transfer such rights to a person who would not have qualified to receive them at admission.

Unlike many other markets (including the Main Market), the Exchange has not imposed any mandatory sunset provisions or time limits. An AIM company may reduce or withdraw such rights at any time following consultation with the Exchange.

6. Corporate governance

AIM companies are no longer required to adopt a recognised corporate governance code or disclose how they comply with such a code under the "comply or explain" model.

Instead, AIM Rule 26 now requires disclosure across the following prescribed governance areas: (i) board composition, (ii) director roles, responsibilities and functions, (iii) remuneration and performance, (iv) risk and controls framework and (v) investor relations. The intention is to provide investors with sufficient understanding of governance arrangements without forcing AIM companies to comply or explain non-compliance with a pre-existing code.

7. Express market admission route

The existing Designated Market route has been replaced by a broader ‘Express Market’ route. This is intended to provide for a quicker and less onerous and admission process for companies already listed on an Express Market (essentially any market overseen by a member of the International Organisation of Securities Commissions. Express Applicants must (i) have had its securities traded on an Express Market for at least 3 years, (ii) not had any fundamental changes to its board or business in the last 12 months, (iii) have a proposed market capitalisation on admission to AIM of at least £20 million, and (iv) have any relevant admission documentation and all disclosure required under the rules of its home market published in English.

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