The Tax Collector is a building type in Pharaoh.
Tax Collectors collect tax revenue from houses. They are somewhat desirable to close to. Like Courthouses, Palaces, and Mansions, Tax Collectors hold a portion of the city's wealth and are susceptible to robbery.
Though Tax Collectors are not required to evolve housing, they are still an integral part of many housing blocks as a source of revenue. At least somewhat comprehensive taxation is beneficial to City Sentiment: if half of the city is heavily taxed while the other half isn't visited at all by tax collectors, city sentiment plummets.
For more information, see Taxation.