Major Japanese banks have been actively increasing their overseas lending in foreign currencies, but the amount of foreign currency deposits is consistently lower than their overseas lending. To address this issue, banks are focusing on acquiring foreign currency deposits, particularly from corporate customers. According to a recent analysis by the Bank of Japan, the outstanding balance of foreign currency deposits at major banks has been increasing recently, driven by existing non-Japanese depositors adding to their balances. The analysis also found that expanding transaction banking services can contribute to containing depositor attrition, extending tenure, and lowering deposit acquisition costs. The Bank of Japan has been collecting granular foreign currency deposit transaction data to enhance its monitoring of foreign currency funding trends. The data includes detailed information on depositors' individual foreign currency deposit transactions, such as currency, deposit amounts, interest rates, maturities, deposit types, and depositor attributes. The analysis revealed that larger depositors tend to have a higher probability of attrition, while depositors with wider deposit spreads exhibit lower attrition probabilities. Additionally, depositors holding a larger portion of transaction deposits show lower attrition probabilities, suggesting that promoting transaction banking services can contribute to securing and retaining a major bank's depositor base. The results also indicated that banks with larger surplus yen funds tend to secure wider deposit spreads, likely due to reduced pressure to acquire additional foreign currency deposits by offering higher deposit interest rates. Overall, the analysis suggests that major banks can maintain a stable depositor base and contain deposit acquisition costs by promoting transaction banking services and building relationships with depositors beyond deposit interest rate considerations.