Property tax is a tax levied or assessed on the owner of property—often real property (real estate)—that is based on the property’s appraised value. Local governments often impose property taxes to finance their school districts, police departments, fire departments, and municipal projects such as construction and maintenance of streets and roads.

Most local government authorities (often counties) allow citizens to dispute or challenge the appraised value of their property through an administrative process initiated with the tax assessor or appraisal district.

In Illinois, property tax is a primary source of revenue for local governments and school districts. The tax is levied on both real estate and personal property, but the majority of revenue comes from real estate taxes. The amount of property tax owed is determined by the property's assessed value, which is supposed to be a percentage of its market value. Local county assessors are responsible for appraising property values. Property owners in Illinois have the right to appeal the assessed value of their property if they believe it is incorrect. This appeal is typically initiated with the local county assessor's office or the board of review. If the dispute is not resolved at the local level, property owners may further appeal to the Illinois Property Tax Appeal Board or even to the courts. It's important for property owners to be aware of the deadlines and procedures for filing an appeal, as these can vary by county.