A defendant must be served a summons within 120 days after the complaint is filed. If not, the court must dismiss the action filed against the defendant, states the Legal Information Institute.
In the United States of America, after a complaint has been filed, the plaintiff has the ability to seek a clerk's seal and signature on a summons, explains the Legal Information Institute. If said summons has been properly filed, the clerk turns it over to the plaintiff to then serve to the defendant. A copy of the summons is addressed to each individual defendant being served within the confines of the complaint.
Under the Federal Rules of Civil Procedure Title II Rule 4(m), the defendant must be served a summons within 120 days of the complaint being filed, as stated in the Legal Information Institute from Cornell University Law School. If the summons is not served within this allotted time, the court must dismiss the action without holding it against the defendant. It also cannot order that service of said summons be made within a specified time. However, if the plaintiff can show a good reason that the summons was not sent within a timely fashion, the court can issue an extension to the service time appropriate to the time period. This rule subsection does not extend to service in a foreign country. Those rule subsections are covered in Rule 4(f) and Rule 4(j)(1).