This paper examines the effect of financial sanctions at the most disaggregated level possible, individual bank accounts. Using data from the Eurosystem’s real-time gross settlement system TARGET2, we provide empirical evidence that sanctions imposed by the European Union on Russian banks following Russia’s aggression against Ukraine in 2014 and 2022 have sizably reduced financial transactions with sanctioned Russian bank accounts, both along the extensive and intensive margins. Among the various sanction measures taken, exclusion from SWIFT, a global provider of secure financial messaging services, turns out to have the largest effects.