On July 4, 2024, the Court of Justice delivered its judgment in the Westfälische Drahtindustrie and Others v. Commission case,[1] addressing Westfälische Drahindustrie GmbH’s (“WDI”) challenge to the Commission’s request for interest payments on the fine imposed on WDI for its participation in a cartel in the prestressing steel sector. This judgment confirms that interest on fines levied by the Commission begins to accrue from the day indicated in the Commission’s decision, even if the EU courts later redetermine the amount of the fine.