Domicile is the place where a person or entity has its primary, permanent home or principal place of business. Domicile is important in the law for determining the state and county in which a person or entity may be sued, vote, and is obligated to pay taxes. For a person with multiple homes or different places of residence, domicile is the place the person plans to return to after being away, and may be indicated by the place where the person maintains important services and relationships, such as banking, driver’s license registration, incorporation, and work/employment. A person or entity is said to be a domiciliary of the domicile.

In Pennsylvania, domicile is defined as the place where an individual has their permanent home or principal establishment and to which they intend to return whenever they are absent. It is a legal concept used to determine various legal obligations and rights, including jurisdiction for lawsuits, voting rights, and tax responsibilities. For an individual with multiple residences, the domicile is typically the location where they have the most significant connections, such as where they vote, where their driver's license is issued, where they have their primary bank accounts, and where they are employed or conduct their primary business activities. For entities like corporations, domicile is usually where they are incorporated or where their principal place of business is located. Establishing domicile affects where an individual or entity can be sued (venue), where they can exercise their right to vote, and where they are required to pay state and local taxes. Changing one's domicile requires both physical presence in the new location and the intent to remain there indefinitely.