Are you AIMing to move to the Main Market?

Are you considering moving from AIM to a Main Market listing?

In this article we examine why many AIM companies are seeking to do so now, some of the benefits of stepping up, and how Travers Smith can help you if you are considering a move.

Why are AIM Companies Moving Now?

Moving from AIM to a listing on the Main Market is a well-trodden path. When AIM launched in 1995 it was expected to be a feeder for the Main Market - since AIM's inception, over 130 companies have stepped-up. But in the last year an increasing number of AIM companies (8) have either finalised a move or announced an intention to move. If all complete on time, 2025 is set to be the biggest year for AIM to Main Market transfers in the last 14 years.

Many reasons for moving to the Main Market are long-standing, but certain factors are driving the current market trend.

Long-standing reasons

Size and maturity: Companies moving from AIM to the Main Market typically have a market capitalisation in excess of £450m. Moving to the Main Market can often symbolise that a company has reached a certain size and level of maturity and has ambitious growth plans for which a Main Market listing would be more appropriate. As a result, Boards often take well-deserved pride in steering their company through the process.

Access to capital and liquidity: The Main Market is considerably larger and more liquid than AIM. During 2024, fifteen times more cash was raised on the Main Market than on AIM and over the same period, average daily trading volumes on the Main Market exceeded those on AIM by a factor of approximately 23. A Main Market listing correlates with better access to capital, increased investor demand and better price discovery/stability. This is primarily a function of company specific size and earnings, but companies typically cite two structural benefits for making the move:

Index inclusion: While AIM companies may be included in the FTSE AIM Index Series, Main Market companies can be included in the headline FTSE UK Index Series. The most ambitious AIM companies typically target inclusion in the FTSE 350 or FTSE 250 indices, with notable success achieved by a handful of companies (including Entain, Melrose Industries and Unite Group), which ultimately grew to enter the FTSE 100. Inclusion in the FTSE UK Index Series increases investor attention and brings meaningful additional demand from index trackers (estimated between 5% and 8%), as well as further demand from investors whose mandates require or favour FTSE UK Index Series inclusion (estimated between 10% and 15%).
Depth and quality of analyst coverage: It's widely acknowledged that the Main Market benefits from broader and better analyst coverage than AIM. More and higher-quality investment research enhances price discovery, widens the audience of potential investors, and facilitates liquidity, new issuance and capital formation.

Corporate governance and investor confidence: A listing on the Main Market, and historically a blue-chip listing in its former Premium Listing Segment, has been recognised internationally as denoting the gold standard in corporate governance and stewardship. Main Market companies have been subject to stricter eligibility criteria on admission, more rigorous regulatory obligations on an ongoing basis, and the more exacting 'comply or explain' requirements of the UK Corporate Governance Code (when compared to the QCA Code adopted by over 90% of AIM companies). Investors have therefore tended to have more confidence in, and to have been more willing to invest in, Main Market companies.

Improved profile: Companies moving from AIM to the Main Market frequently report an improvement in their public profile and enhanced visibility as one of the principal reasons for the move, with corresponding benefits for dealing with investors, customers, suppliers and lenders.

New factors

UK Capital Markets Reforms: When AIM launched it was designed to offer a relatively flexible regulatory framework and be a low-cost alternative to listing and raising capital on the Main Market. In many respects that continues to be the case. However, as part of the UK's capital markets reforms (which have sought to re-invigorate UK markets, boost competitiveness and encourage more companies to list in London), new UK Listing Rules applicable to Main Market companies came into effect in July 2024. These meaningfully simplified the Main Market regime and have narrowed the gap between the regulatory burden applicable to the Main Market and the burden applicable to AIM. The new prospectus regime coming into effect on 19 January 2026 will further narrow the gap, making it easier for Main Market companies in particular to raise significant amounts of secondary capital¹. On 21 November 2025 AIM announced a planned consultation to reposition the AIM Rules during H1 2026, confirmed it will consider certain derogations from the AIM Rules effective immediately, and make changes to current guidance to support that approach. Positive steps have been taken indicating good direction of travel, but as yet the AIM Rules have not been materially relaxed. A summary comparison of the Main Market and AIM regimes is included below.

Tax: AIM investors have, since 1996, benefitted from 100% inheritance tax relief on AIM shares, if held at death for two or more years. In the Autumn Budget 2024 the Chancellor halved this relief (with effect from 6 April 2026), and there's concern that given the UK's fiscal position, it could be the subject of further attention in future. Inheritance tax relief undoubtedly encouraged investors to buy and hold AIM stocks, and it's relatively common for 20% or more of an AIM register to comprise so called 'IHT investors.' This relief still exists (albeit set at a lower level) and it's still an attractive feature of AIM, but many AIM companies report they are now less constrained by fiscal inertia and a shareholder base strongly opposed to stepping up.

Main Market companies will be permitted to issue up to 75% of their existing share capital in a rolling 12-month period without publishing a prospectus, a significant increase from the current 20% threshold. There will still be no equivalent restriction on AIM. Neither AIM nor Main Market companies will be required to publish a prospectus where they make an offer of shares to the public

Our experience

Travers Smith has a wealth of experience advising AIM listed companies, Sponsors and Nomads on AIM to Main Market transfers, including on a number of announced transactions in 2025.

We have particular expertise navigating challenges faced:

By acquisitive companies with complex financial histories.
In relation to IHT investors selling down.
In relation to index inclusion and UK re-domiciliation.
In relation to the application of the new prospectus regime, which comes into effect on 19 January 2026.
Preparing companies for UK Listing Rules and UK Corporate Governance Code compliance.

A selection of our recent work includes: