Service of process is the procedure by which a party to a lawsuit gives an appropriate notice of initial legal action to another party (such as a defendant), court, or administrative body in an effort to exercise jurisdiction over that person so as to enable that person to respond to the proceeding before the court, body, or other tribunal.
Notice is furnished by delivering a set of court documents (called "process") to the person to be served.
Each jurisdiction has rules regarding the appropriate service of process. Typically, a summons and other related documents must be served upon the defendant personally, or in some cases upon another person of suitable age and discretion at the person's residence or place of business or employment. In some cases, service of process may be effected through the mail as in some small claims court procedures. In exceptional cases, other forms of service may be authorized by procedural rules or court order, including service by publication when an individual cannot be located in a particular jurisdiction.
Proper service of process initially establishes personal jurisdiction of the court over the person served. If the defendant ignores further pleadings or fails to participate in the proceedings, then the court or administrative body may find the defendant in default and award relief to the claimant, petitioner or plaintiff. The defendant may contest the default in his or her home state. Service of process must be distinguished from service of subsequent documents (such as pleadings and motion papers) between the parties to litigation.
Service of process in cases filed in the United States district courts is governed by Rule 4 of the Federal Rules of Civil Procedure. In England and Wales, the rules governing service of documents are contained within Part 6 of the Civil Procedure Rules 1998. In Canada the rules vary from province to province and can be governed differently depending on what the type of case (i.e. family, small claims, criminal, etc.).