Point of Sales (POS) terminals are provided by the banking and financial institutes to perform cashless transactions. Over the time due to different conveniences, use of digital money and online card transactions increased many folds. After each successful payment transaction at the POS terminals, a transaction log is sent to the POS terminal provider with payment-related financial data such as date and time, amount, authorization service provider, cardholder’s bank, merchant identifier, store identifier, terminal number, etc. These data are useful for analytical processing which are useful for business. This paper proposes to process these huge transactional data using ETL process and thereafter construction of a data warehouse (DW) which enables the POS provider to employ certain analytical processing for business gain such as knowing own market share as well as position in market with respect to card payments, geographic location-wise business profiling, own as well as competitor’s customer segmentation based on monthly card usage, monthly amount spent, etc. © Springer Nature Singapore Pte Ltd. 2019.