We investigate the integration of euro-zone retail banking markets by comparing convergence and cointegration measures. As an innovation to the literature convergence measures are exposed to a difference-in-differences methodology which allows both, identifying the impact of the single currency and benchmarking euro zone-specific from global integration effects. We find that euro-zone convergence has largely been a result of integrating wholesale markets after the elimination of exchange rate risks. After 1999 integration is mainly observed for a restricted “convergence club” excluding germany, ireland and belgium. Moreover, convergence is at least partly a global rather than euro zone-specific process.