System and method for validating a payment. The method can include obtaining a first account identifier, accessing a database containing a plurality of risk scores, each one of the plurality of risk scores being associated with one of a plurality of account identifiers, obtaining a first risk score from...http://www.google.com.au/patents/US20050283429?utm_source=gb-gplus-sharePatent US20050283429 - Scored negative file system and method
