The UK Supreme Court gave its judgment in Mastercard Incorporated and others (Appellants) v Walter Hugh Merricks CBE (Respondent) [UKSC 2019/0118] on 11 December 2020.  It confirmed the decision made by the Court of Appeal that a representative applying for certification of a class must show that they have a method with a realistic prospect of assessing loss across the whole class and that the data required to apply that methodology is likely to be available at trial. This is a relatively low bar to meet.  It means that it will be relatively straightforward to pursue class actions litigation in the UK and to secure funding to do so – and that we will not see US-style mini trials poring over evidence at the certification stage.  The UK Supreme Court did acknowledge that the Competition Appeal Tribunal has a wide discretion in determining whether to certify and could have dismissed the application on other grounds – nonetheless, it must now reconsider the Merricks application again