In a lawsuit brought by the United Kingdom, the European General Court ruled that the European Central Bank cannot mandate that central clearinghouses that clear euro-denominated trades be located solely in one of the 19 countries where the euro is used as a fiat currency, as opposed to in the UK too. The ECB had implemented such a requirement, arguing that the “negative externalities” that could occur from delays in the settlement of payments if clearinghouses were located outside the Eurozone justified adoption of the requirement. The General Court ruled, however, that the ECB does not have the authority to regulate clearing systems, as its authority only extends to payment systems. The ECB may appeal the court’s decision within two months to the European Court of Justice—the pan-European equivalent of the US Supreme Court for matters related to European law. The General Court is the appellate court below the ECJ.