In HMRC v MCX Dunlin (UK) Ltd [2021] EWCA Civ 186 (17 February 2021), the Court of Appeal overturned the High Court’s decision that interest was due on repayments of liabilities to petroleum revenue tax (PRT) dating from the 1980s which had been met by crediting advance PRT (APRT), holding both that the company’s claim was an abuse of process and that it failed on the merits.