Property tax law refers to the body of regulations and statutes that grant government authority to levy fees on various items that are owned by people under the jurisdiction of that government. Technically, a property tax could refer to any tax on any item that is accurately defined as property, which includes a person's personal property. However, property tax law conventionally refers to the body of law that of which surrounds the taxation of real property, and this is a topic with broad and deep treatment under this law. Jurisdictions that allow people to privately own land in a legal system that stems from English common law also offers a means for the government to levy a tax on that land. Taxation on real property ownership is the general purview of a local jurisdiction, which uses the taxed money to raise funds to activate local public projects. The general underlying theory for real property tax is that the owners of such land have a vested interest in the workings of the public within that area and that they should contribute to the upkeep of services and works benefiting that community. Every jurisdiction comes with its own tax law that is dependent on the needs of its area. The local tax code will dictate the fees that the jurisdiction assesses, as well as the rate at which owners will be charged. These are assessed at the property level rather than the owner; this means if the owner does not ever use the property, they must still pay the taxes. In the United States, the states each govern their own property tax laws that authorize its local municipal governments to use real property tax to generate its revenue. The two types of taxes property owners will pay include a yearly tax and a transfer tax upon the sale of the property. The former is assessed based on the value of the property, and then it is established by way of an official assessment by a public official. The latter is generally just a percentage of the sale price. When the property value depreciates, or decreases over a period of time, an owner might find that they are no longer paying within the line of the actual value of their property. When this occurs, they must file an appeal with the local tax authority. Successful appeals can mean an annual savings of thousands, so owners may want to hire a lawyer to win them.