Security alerts in supplier transactions

In one embodiment, a computer-implemented method comprises, using an e-procurement platform instance that is programmed to host thousands of user accounts that are associated with a plurality of different entities, receiving, from a buyer computer, supplier payment account data for a dataset representing a payment to a supplier; creating a cryptographically secure fingerprint based on the supplier payment account data; using the fingerprint and at least a portion of the supplier payment account data, programmatically transmitting a structured database query to a digital data repository, the digital data repository comprising at least hundreds of thousands of records of transactions that included other datasets representing other payments; in response to the querying, receiving a result set of a plurality of supplier payment datasets, based on the records of transactions, the supplier payment datasets representing past submissions of payments to the same supplier payment account that the fingerprint represents; based on the result set and a plurality of programmatic rules, calculating one or more notification metrics and selecting a notification from among a plurality of programmed notifications and transmitting, to the buyer computer, presentation instructions which when rendered using the buyer computer cause displaying the one or more notification metrics and a notification text.