A target audit methodology to provide a transaction-based detail of errors in an environment with a high volume of transactions. The primary components comprise a distributed computer network, such as the global Internet, coupled to numerous databases and a workstation. A Random Sample Query is used to pull a statistically valid sample from a general population of transactions to identify initial transaction errors. The initial transaction errors are analyzed to determine parameters for identifying other similar errors with a high probability of occurrence within the total population of transactions. A Possible Error Query is designed to retrieve these specific error types and is processed against the population of transactions. The results of the Possible Error Query are assigned financial impact and detailed for the client by individual transaction in an invoice.