A system and method for detecting fraud when facilitating a payment transaction over a global wide area network. The method comprises receiving a sale information, receiving a payment information from a buyer, and analyzing a transaction information for fraud. If the analyzing indicates fraud, an enhanced transaction information is communicated to a human for fraud analysis. In one embodiment, the method comprises performing rule-based analyses to determine whether the transaction appears to be fraudulent. Rule-based analyses may include suspect data rules and velocity rules. Velocity rules generally determine whether there has been excessive activity that may lead to a conclusion that the transaction may be fraudulent. Suspect data rules are used to determine whether the billing, shipping, selling addresses, telephone numbers, and account numbers, and other data are in a syntactically correct format and whether they exist. In one embodiment, the method further comprises performing simple screening of the transaction information. In one embodiment, the method further comprises seeking approval from a third party such as a financial institution based on the payment information. The method may be implemented as part of a system that includes personal computers, server computers, and other personal computing devices, some of which may communicate over the Internet, and others which may communicate via dedicated communication lines.