In antiquity, publicans were public contractors, in whose official capacity they often supplied the Roman legions and military, managed the collection of port duties, and oversaw public building projects. In addition, they served as tax collectors for the Roman Republic, farming the taxes of the Roman provinces, and bidding on contracts for the collection of various types of taxes. Importantly, this role as tax collectors was not emphasized until late into the history of the Republic. The publicans were usually of the class of equites.

A tax collector is a person who collects unpaid taxes from other people or corporations on behalf of a government. The term could also be applied to those who audit tax returns or work for a revenue agency. Tax collectors are often portrayed negatively, and in the modern world share a similar stereotype to that of lawyers.