This Practice Note is for use when determining applicable law where the contract was entered into on or after 1 January 2021. For contracts entered into before 1 January 2021, a different applicable law regime will be applied by the UK courts. Which regime will apply will depend on the date on which the contract was entered into. For guidance on the different regimes and their interrelationship, see Practice Note: Applicable law regimes. This Practice Note refers to UK Rome I, Regulation (EC) 593/2008. This regulation is applied when determining applicable law in cases in which the contract was entered into on or after 1 January 2021. Originally known as Retained Rome I, since 1 January 2024, it is known as Assimilated Rome I—the change is to the name only and not the provisions within the regulation. Authorities may refer to the regulation using either name and so, for ease of reference, the regulation is referred to as UK Rome I in this Practice Note. For information on assimilated law,