All change for market abuse? EU reforms to issuer disclosures impact dual EU-UK compliance arrangements

Since Brexit, UK and EU market abuse regimes have remained broadly aligned. Companies with securities admitted to trading in both the UK and the EU – often via a London share listing alongside EU traded debt – have been subject to parallel disclosure obligations under the UK and EU versions of the Market Abuse Regulation (UK and EU MAR). The broad alignment between the two regimes has made dual compliance relatively straightforward (although, as shares tend to be more price sensitive than debt, actual disclosure thresholds may differ between financial instruments).

With effect from 5 June 2026, however, EU MAR has been updated with two main changes for disclosure‎‎: when an issuer must disclose inside information in relation to a protracted process, and the conditions that must be met before an issuer can delay disclosure to protect its ‘legitimate interests’.  

So what has changed in EU MAR, and what does this mean in practice for issuers with both UK and EU obligations?

Intermediate steps

What has changed?

While recent changes to EU MAR do not significantly amend the definition of inside information – which remains substantially the same across UK and EU MAR – they do change when that inside information must be disclosed.

The starting point for both regimes is that an issuer must inform the public as soon as possible of any inside information which directly concerns that issuer, subject only to limited grounds for delay. This continues to be the case for any item of inside information under UK MAR.  

Under EU MAR, however, an issuer is no longer required to disclose inside information if it relates to an ‘intermediate step’ in a protracted process, provided that the information can be kept confidential. Intermediate steps can still constitute ‘inside information’ – a fact that remains relevant for other aspects of EU MAR, such as the offence of unlawful disclosure or the insider trading prohibitions – but the EU regime now ‘decouples’ possession of inside information about an intermediate step from the requirement to disclose it. A disclosure obligation only applies once the ‘final circumstances or final event’ has occurred at the end of the protracted process, at which point the market must be notified as soon as possible (subject only to the usual limited grounds for delay).

What does this mean in practice?

In many situations, the timing of UK and EU MAR announcements is likely to remain aligned. Although UK MAR imposes an immediate disclosure obligation for intermediate steps, an issuer can often meet the conditions necessary to delay that disclosure – for example, it may be able to delay disclosure of early milestones in an M&A process to avoid jeopardising ongoing negotiations. This may mean that in practice no disclosure is made under either regime until the end of the protracted process. Where delay is not possible under the UK regime, however, an issuer subject to both UK and EU rules may need to disclose earlier under UK MAR – and as that UK disclosure will mean the information is no longer confidential, this will also trigger an immediate EU MAR disclosure obligation.  

Even where there is no difference in the timing of announcements under the two regimes, there will be administrative changes for issuers. In the UK, if an intermediate step constitutes inside information, delaying its disclosure will require the issuer to keep under review whether the conditions permitting delay are met and to maintain specified internal records of those assessments. When disclosure is made, the issuer must also inform the FCA that there was a period of delay and, if requested, provide it with a written explanation of how the conditions for delay were met. None of those administrative requirements will apply under EU MAR, because the inside information related to a mere intermediate step did not give rise to a disclosure obligation in the first place (so long as it remains confidential).

EU MAR will instead require issuers to analyse whether an item of inside information counts as an ‘intermediate step’ in a protracted process for the purposes of the new rules. An EU Delegated Regulation (expected shortly to be published in the Official Journal) sets out a non-exhaustive list of 35 protracted processes and what will constitute the ‘final event’ requiring disclosure as soon as possible, unless it can be delayed on the usual ‘legitimate interests’ basis. Inclusion on this list does not mean that a process will always be inside information, and it is also possible for issuers to make a case-by-case assessment of circumstances outside the listed processes. Where the updated rules apply, an issuer will be expected to be able to substantiate the reasons for its identification of the final event and the relevant moment of disclosure, meaning they will in practice need to maintain internal records of their analysis. A key difference from the UK MAR position, however, is that this will generally be a one-off determination without the ongoing review requirement that applies to delay conditions.

Delay conditions

What has changed?

Under UK MAR, an issuer can delay disclosure of inside information if certain conditions are met. These are, broadly, that immediate disclosure is likely to prejudice the issuer’s legitimate interests, the delay is not likely to mislead the public and the information remains confidential.  

EU MAR has now amended one limb of this test, replacing the requirement that the delay is not likely to mislead the public with a requirement that the delayed inside information is not in contrast with the latest public announcement or other type of communication by the issuer on the relevant matter. This new EU MAR provision is based on ESMA MAR Guidelines on delay in the disclosure of inside information, the pre-Brexit version of which remain relevant in the UK, which suggest delay is likely to mislead the public when the inside information is materially different from the previous public announcement of the issuer on the relevant matter.  

The UK version of the MAR Guidelines does, however, include two further non-exhaustive examples of when delay might mislead: if the inside information relates to the fact that the issuer’s financial objectives are not likely to be met (where they were previously publicly announced), and where the information is in contrast with the market’s expectations (where those are based on signals previously sent to the market by the issuer). These situations are not covered in the amended EU MAR, but they will remain relevant in the UK.  Arguably, these further examples may be seen as a subset of the updated EU MAR provision, but issuers should keep an eye on any developing market practice in this area. In addition, ESMA has recently consulted on proposed revisions to the EU version of the MAR Guidelines, which may introduce further differences between the EU and UK regimes when finalised (expected by the end of 2026).

What does this mean in practice?

While this divergence could potentially lead to unusual cases where delay is permitted under one regime but not the other, the circumstances permitting delay are likely to remain aligned in the EU and the UK in most situations.  Issuers should however be aware of the differences and ensure that they refer to the provisions and guidance applicable to each regime when considering the conditions for delay.

Conclusion

Although the practical impact of these changes may be limited in most situations, issuers should ensure that relevant decision-makers (such as a disclosure committee) are aware of the different rules that now apply, and that internal procedures are updated to cover the requirements of the two regimes.

Issuers facing dual compliance should continue to ensure they assess correctly the point at which an intermediate step constitutes inside information. Although a premature determination will not trigger a disclosure obligation under EU MAR, it will still do so under UK rules – and while it may then be possible to delay that UK disclosure, this is not guaranteed, and any period of delay will in any event trigger the usual time-consuming assessment and record-keeping obligations. Issuers should also review internal procedures to ensure they can substantiate the appropriate final event or circumstance that will trigger disclosure under EU MAR at the end of an identified protracted process. Finally, where disclosure is being delayed to protect the legitimate interests of an issuer, relevant decision-makers should be aware of the different conditions that now apply under UK and EU MAR, and (where relevant) ensure that both tests are met and reflected in internal records on an ongoing basis, also taking into account any developing market practices in the EU as the new regime embeds.