The German Federal Constitutional Court (BVerfG) has for decades used informality to establish, build, and protect its authority. Yet, as the political landscape has shifted in recent years, in particular since the end of the Merkel-era Grand Coalition and the rise of the right-wing populist AfD, several longstanding informal practices and institutions have become politicized. Those concern extra-judicial activities of judges, regular informal meetings between the Court and the government, and privileged early access to the Court’s press releases for certain journalists. This Article first introduces various forms of informality that the BVerfG employs in its internal self-administration and the judicial-legal culture in general, before tracing how, why, and by whom the three aforementioned practices of informality are challenged. Ultimately, this Article analyzes how the Court and its judges respond to the politicization of informality, and in particular how it triggered processes of formalization of judicial behavior and changes in institutional communication.