After five years of unpaid taxes on a property, the Auditor holds what is called the May Tax Sale.  These delinquent properties are sold so the various providers of taxpayer services (i.e. school, city services, water, etc.)  can be reimbursed for their operating expenses.  Buyers at the sale are required to bid on these properties and sometimes they sell for more than the amount of property tax owed.  This excess amount is then returned to the original property owner.  If the original owner cannot be contacted, the excess funds are sent to the Utah State Treasurer Unclaimed Property Division.