Adverse possession—sometimes called squatter's rights—occurs when a person or entity who does not own a certain piece of real property occupies or uses it in a way that is adverse to the owner of the property—meaning the use is in conflict or at odds with the property owner’s interests.

If this adverse possession or use of the property meets the legal standard for adverse possession—often described as use that is continuous, exclusive, hostile, open, and notorious—and continues for the prescribed period of time (usually specified in the state statute)—the person or entity adversely possessing or using the property will acquire ownership of the property (title). This ownership will result in the changing of boundary lines.

Because the required adverse possession must be open, obvious, and adverse to the owner’s interests, title may only be acquired by adverse possession to the portion of property that is used in that way.

Adverse possession laws vary from state to state and may be located in a state’s court opinions (also known as common law or case law) or, more often, in its statutes.

In Utah, adverse possession laws allow a person to gain legal ownership of a property by possessing it in a manner that is open, notorious, exclusive, continuous, and hostile for a period of seven years, as per Utah Code § 78B-2-214 to § 78B-2-215. The possessor must also pay property taxes during this period to claim adverse possession. If these conditions are met, the individual may be able to acquire title to the property, potentially altering the boundary lines. It's important to note that adverse possession is a complex area of law, and specific circumstances can significantly affect the application of these laws. Therefore, individuals involved in adverse possession claims often seek guidance from an attorney to navigate the legal requirements and processes.