1. An apparatus comprising: a processor to: receive a user selection of an audit data set including a plurality of exceptions, wherein each exception of the plurality of exceptions represents an instance of misbilling associated with the audit data set, wherein the audit data set is selected from a plurality of billing data sets, each billing data set of the plurality billing data sets including corresponding billing data that has been extracted by the processor from a database; apply a first audit rule to audit the audit data set and produce first audit rule results, wherein the first audit rule results identify a first subset of exceptions of the plurality of exceptions within the audit data set; apply a second audit rule, distinct from the first audit rule, to audit the audit data set and produce second audit rule results, wherein the second audit rule results identify a second subset of exceptions of the plurality of exceptions within the audit data set; present the first subset of exceptions and the second subset of exceptions to a user via a results user interface; and receive a selection of a particular audit rule, wherein the particular audit rule is one of the first audit rule and the second audit rule, and wherein the particular audit rule is selected based on the first audit rule results and the second audit rule results.