Under the UK Market Abuse Regulation, an issuer and any person acting on behalf of an issuer or on its account must each:

• draw up a list of all persons who have access to inside information and who are employees or otherwise performing tasks through which they have access to inside information, and keep such list updated;
• send their list to the FCA as soon as possible upon request;
• take all reasonable steps to ensure that any persons on their insider list acknowledge in writing the legal and regulatory duties entailed and are aware of the sanctions to which they are subject; and
• ensure that their insider list is kept for a period of five years after it is drawn up or last updated.¹

¹ Regulation 596/2014 of the European Parliament and of the Council of 16 April 2014 on market abuse (market abuse regulation) (MAR), as retained in the UK by the Market Abuse (Amendment) (EU Exit) Regulations 2019/310, art. 18. Note that article 18 was amended by section 30 of the Financial Services Act 2021 to make clear that both issuers and any person acting on their behalf or on their account such as advisers are required to make their own insider lists. Section 30 came into force on 29 June 2021.