AIM Rules explained: What the 2026 changes mean for companies

Following the London Stock Exchange’s June 2026 consultation (AIM Notice 62), the proposed amendments to the AIM Rules for Companies are now in force as of 5 August 2026. The revision to the rules intends to give AIM companies greater flexibility while simplifying and making certain admission and transaction processes more efficient. 

1. Working capital and financial disclosures

The revised AIM Rules remove the traditional working capital statement and replace it with more detailed disclosures designed to give investors a clearer understanding of the company’s overall financial position and funding requirements.

The change moves away from the previous requirement for directors to provide a formal statement that the company has sufficient working capital for at least 12 months. Instead, the emphasis is on providing investors with a clearer picture of how the business is funded, its expected cash requirements and the potential need for additional capital. This is particularly relevant for growth and early-stage companies, where cash burn, investment requirements and reliance on future fundraising can be significant.

For reporting accountants, the removal of the formal working capital statement does not mean that the underlying financial analysis is no longer required. The reporting accountant should still undertake detailed work over the company’s cash flow forecasts, available cash, debt and financing facilities, working capital requirements, capital expenditure, contractual commitments and other significant financial obligations. Management’s assumptions should be assessed against historical performance, current trading and supporting evidence, with particular attention given to the timing and quantum of expected cash inflows and outflows.

There should also be consideration of downside scenarios and sensitivities, particularly where the company’s ability to execute its business plan depends on future fundraising. The reporting accountant should assess when additional funding may be required, how much may be needed and the risks if that funding is delayed or unavailable. The LSE has also clarified that directors’ assessment of future funding requirements is based on a “reasonable opinion”, meaning that the conclusion should be objectively supportable rather than based solely on management optimism.

For reporting accountants, this means that financial due diligence remains an important part of the AIM admission process and the changes likely alter the nature and presentation of the work rather than eliminate it.

We expect, certainly initially, that there will be varying requirements amongst Nomads to provide the comfort still required under the revised rules. Indeed, we are already working with two that are taking different approaches. At Kreston Reeves, we will always discuss the requirements with each client to ensure we flex our reporting and offer the value and efficiency these new rules have been developed to provide.

Alongside changes to the working capital and financial disclosures, further amendments include the following:

2. Capital access window

A new voluntary capital access window has been introduced. This allows AIM companies to request a temporary suspension of their securities while undertaking an equity fundraising. The mechanism is intended to provide companies with greater flexibility when managing a fundraising process and may help reduce market volatility during the transaction.

3. Reverse takeovers

The rules relating to reverse takeovers have been amended so that shareholder approval is no longer required solely because a transaction exceeds 100% under one or more of the class tests. 

Instead, the focus is on whether the transaction results in a fundamental change to the AIM company’s business, board or voting control. Where an acquisition, or series of acquisitions within a 12-month period, exceeds 100% under any of the class tests, the company must consider, with the assistance of its nominated adviser, whether the transaction constitutes such a fundamental change.

4. Substantial transactions

The class-test threshold for determining whether a transaction is a substantial transaction has increased from 10% to 25%. This brings AIM more closely into line with the Main Market and should reduce the number of transactions that fall within the substantial transaction regime.

5. Express market route

The previous AIM Designated Market Route has been replaced by a new Express Market Route. The new route expands the jurisdictions from which companies may qualify and reduces the required Schedule One announcement period to three clear business days. An accelerated process has also been introduced for companies seeking admission to the Main Market, potentially making the overall admission process more efficient. 

6. Dual market admission

A new dual market admission route has been introduced for companies seeking simultaneous IPO admission to both an Express Market and AIM. Such companies may rely on their Express Market admission document, provided that they raise a minimum of £6 million.

7. Buyer-beware disclosure

The revised rules introduce specific buyer-beware wording into AIM admission documents. A prominent bold statement must now appear on the first page confirming that AIM is a buyer-beware market.

This reinforces the importance of investors undertaking their own assessment of an AIM company and highlights the continuing importance of robust financial, commercial and legal due diligence in corporate transactions.

8. Proxy adviser engagement

AIM companies may now voluntarily disclose details of their engagement with proxy advisers. This provides companies with greater flexibility over how they communicate their approach to shareholder engagement and governance matters.

9. Third-party commentary and right of reply

The revised rules also provide AIM companies with an express ability to respond to third-party commentary and market speculation. This gives companies greater scope to address potentially misleading or inaccurate information circulating in the market. 

Corporate finance implications

Overall, the revised AIM Rules provide greater flexibility around fundraising, acquisitions and market admission while placing increased emphasis on clear financial disclosure and investor due diligence. For corporate finance professionals, the changes to working capital and funding disclosures, reverse takeover rules and the substantial transaction threshold are likely to be particularly relevant when advising on acquisitions, disposals, fundraising and admissions to AIM.

The revised framework should therefore be considered carefully when assessing transaction structures, determining whether shareholder approval is required and planning the financial and commercial due diligence process.

Considering how the new AIM Rules could affect your business or transaction? Our corporate finance team can help you understand the changes and assess what they mean for your funding, reporting and transaction plans. Get in touch with our team to discuss your options.