This annotation reports on aspects of EU electronic communication law in the Hungarian Supreme Court’s judgment of 26 February 2013, which annulled the results of the 900 MHz frequency auction carried out by the Hungarian National Media and Electronic Communications Authority in 2011-2012.1 In particular, the Supreme Court said that the NMHH should have conducted a market analysis procedure before imposing upon incumbent mobile operators an obligation to provide national roaming services to a new entrant. The Supreme Court reached this conclusion after analysing the Authorisation, Access and Framework Directives, the Charter of Fundamental Rights of the European Union and the European Convention on Human Rights. The judgment is significant, because it provides guidance on how national regulatory authorities can force incumbents to help new entrants with national roaming arrangements.