Advisor obligations under MAR

What the regulation requires, and where advisors commonly fall short

Advisors working on transactions involving listed companies are subject to their own obligations under the Market Abuse Regulation (MAR). Those obligations do not depend on the issuer's compliance team reminding you of them, and they do not disappear because another firm on the deal is also keeping a list. This article sets out what you are required to do and why.

Who this applies to

MAR applies to any person acting on behalf of or on the account of an issuer in connection with inside information. In practice, that covers lawyers, investment banks, accountants, financial advisers, and PR firms who receive inside information as part of their engagement. If you have been brought onto a transaction and given access to non-public, price-sensitive information about a listed company, you are in scope.

What MAR requires of advisors

Maintaining your own insider lists

Article 18 of MAR requires any person acting on behalf of or on the account of an issuer to keep their own insider list. This is a separate obligation from the issuer's. Your list must cover every individual within your organisation who has been given access to inside information in connection with the relevant matter.

Each entry must be in the prescribed format, which includes full personal details for each individual, the reason for their inclusion, and the precise date and time they were given access. The format requirements are set out in Commission Implementing Regulation (EU) 2016/347 and, for UK purposes, the equivalent UK retained law.

Maintaining a list after the fact, or relying on email trails to reconstruct one, does not meet the standard. The list must be kept in real time and be available to the relevant regulator on request.

Appearing on the issuer's list too

A common source of confusion is the relationship between the issuer's list and your firm's own list. Being included on your firm's internal list does not remove the issuer's obligation to include your contact details on theirs.

ESMA's Q&A is explicit on this point: the two lists are independent obligations. An issuer must record the natural person who acts as the primary contact for each adviser, including their full personal details, even where that individual is already on the adviser's own list. If you are the primary contact for your firm on a transaction, you will be on two insider lists. That is correct, and it is what the regulation requires.

This is also the reason you receive acknowledgement requests from issuers. Under MAR, issuers must take all reasonable steps to obtain written acknowledgement from each insider that they are aware of their obligations. That request is not optional for the issuer to make, and providing the acknowledgement is not optional for you to give. Industry guidance from the GC100 confirms that issuers should include natural persons as contacts for each adviser and obtain acknowledgements accordingly.

Notifying individuals on your list

When a person is added to your insider list, they must be informed of their obligations under MAR. This notification should be documented. When the matter concludes and access is no longer required, the list is closed out but retained for a minimum of five years.

Dealing restrictions

Any individual on your firm's insider list is in possession of inside information and is prohibited from trading in the relevant financial instruments for as long as they remain on the list. The dealing prohibition under MAR Article 14 applies from the moment a person receives inside information, regardless of whether they have been formally notified. Where there is any doubt about whether a person holds inside information, the safer course is to treat them as if they do.

Recordkeeping

All decisions relating to inside information, including the assessment of whether information has reached the threshold for inside information, must be documented and retained. If a disclosure is delayed under MAR Article 17(4), the conditions for delay must be assessed and recorded at the time of the decision, not retrospectively.

Where advisors tend to run into difficulty

Practical problems arise in a few recurring areas.

Timing. The obligation to maintain an insider list begins when inside information is created or received, not when a formal engagement letter is signed. Advisors who begin work on a matter before documentation is in place are still in scope from the moment they receive the information.

Scope of individuals. Insider lists are sometimes kept only for the lead team. Support staff, document reviewers, and others who receive the information as part of their work must also be included if they have access to inside information, even if their involvement is limited or administrative.

The acknowledgement process. Advisors occasionally push back on acknowledgement requests from issuers, treating them as administrative friction. They are a regulatory requirement. Providing a written acknowledgement of your MAR obligations is part of what the regulation expects from you when you are engaged on a transaction involving inside information.

The permanent insider list is not a shortcut for advisors

One further point worth flagging is the permanent insider list. MAR allows issuers to maintain a single permanent insider list covering all individuals with routine access to inside information, rather than separate deal-by-deal lists. Some advisors assume this means they can do the same: keep one running list of anyone who has ever touched inside information across all matters and call it done. That is not how it works. The permanent insider list is a mechanism for the issuer, covering standing insiders such as senior management and certain board members. Advisors are still required to maintain matter-specific lists, one per engagement, capturing precisely who had access to inside information in connection with that transaction and when. A single consolidated firm-wide list that pools all matters and all individuals does not satisfy Article 18, and regulators reviewing it would have no way to verify access controls for any individual engagement.

Further reading

For a comprehensive overview of how MAR applies across the transaction lifecycle, including how to identify inside information, handle market soundings, and meet recordkeeping requirements, see our MAR navigation guide for advisors.

For practical questions and answers on the specific mechanics of the acknowledgement process and dual-list obligations, see Q&A: your role as an advisor under MAR.

InsiderList supports advisor teams in maintaining compliant insider lists, capturing acknowledgements, and keeping audit-ready records across every matter they work on. If you would like to see how the platform works, book a demo.