Legislation laying down the first two pillars of the institutional system of the Banking Union was finalised in April 2014. In accordance with the regulations, non-euro area Member States, including Hungary, may notify the ECB at any time if they wish to participate in the common system even before the euro is adopted. The paper aims at summarising the possible pros and cons vis-à-vis the Banking Union from a Hungarian perspective. It highlights the reasons for not opting in at the inception of the new supervisory system and also gives indications about those major milestones that could give rise to the reconsideration of the present position. In its existing form, the single supervisory and crisis management mechanism has not achieved the initial target, i.e. the separation of the stability of national banking systems and the fiscal capacity of Member States and the elimination of interdependencies. In addition, close cooperation implies weaker powers than those provided by actual membership, and the separation of central bank and supervisory functions carries risks in non-euro area countries. By contrast, the attraction of Banking Union membership lies in the opportunity to join a uniform European system, a wider analyst base and ultimately, the “ammunition” of the EUR 98 billion available for crisis management in comparison to the Hungarian banking system. In October 2013, a uniform supervisory system integrated into the central bank was set up in Hungary, and the domestic resolution institutional system was complete by the end of 2014. Therefore, until the finalisation of the Banking Union through the creation of the common deposit insurance fund and a common fiscal backstop, it is reasonable to put the decision to join on hold; indeed, such a decision should be made in light of several factors presented in this study.