An apparatus and method automatically verifies online transactions, such as credit card charges, made by a customer of a bank or financial institution. A browser “plug-in” is used to monitor a first party use of the internet to detect online transactions and create transaction data. The transaction data is forwarded to the financial institution to correlate with transaction data received independently from the other party in the transaction. The financial institution can provide the customer with alerts, such as online purchase warnings, if there are problems or discrepancies between the data from the first party and the data provided by the second party. The transaction data can also be used in other ways to provide information to the financial institution's customers.