Cart judicial reviews constitute the largest single group of claims for judicial review in the High Court. However, they are difficult to study because they rarely result in a High Court judgment and thus are reflected in the popular case law databases. I analysed the best public source of information on the fate of successful Cart judicial reviews—Upper Tribunal decisions following successful Cart claims from 2018 to 2020 selected programmatically from a dataset of over 42,000 — mostly unreported — decisions. Thus, I can discuss the key aspects of successful Cart challenges, including the question what claims succeed in meeting the ‘second-tier appeals’ test for permission set in CPR 54.7A(7). This study complements the previous quantitative study on rates of success in Cart and non Cart judicial reviews and contributes to the broader discussion on the appropriateness of retaining the Cart procedure in the context of the proposal to discontinue Cart claims made by the Independent Review of Administrative Law and adopted by the Government in the Judicial Review and Courts Bill.