ESMA has published its final guidelines on transaction reporting, order record keeping and clock synchronisation under MiFID II. The guidelines, which apply to investment firms, trading venues, approved reporting mechanisms (ARMs) and competent authorities, will apply from 3 January 2018. The guidelines aim to provide guidance on compliance with the reporting and order record keeping provisions of MiFIR and the relevant RTS to ensure consistency in the application of these requirements. In particular, the guidance is focused on the construction of transaction reports and of the order data records field by field for various scenarios (a non-exhaustive list) that can occur.