Proof of service is a document, certificate, or filing showing that legal papers were delivered or served in the required way.
It tells the court how, when, where, and on whom service was made. Depending on the rule, proof of service may be signed by a process server, attorney, party, clerk, sheriff, or other authorized person.
Why proof of service matters
Courts need a reliable record that required documents reached the other side or were served through an approved method. Without proof of service, a court may hesitate to act on a motion, enter default, enforce a deadline, or conclude that a party had legally sufficient notice.
Proof of service is especially important because the consequences of notice can be serious. A party who was properly served may need to respond by a deadline. A party who was not properly served may challenge later proceedings.
Where it appears
Proof of service appears after service of summons and complaint, motions, discovery papers, notices, orders, subpoenas, and other litigation documents. It may be filed as a separate form, attached certificate, affidavit, declaration, or electronic filing entry.
How it differs from nearby terms
Proof of service is different from service of process. Service is the act of delivering legal papers under the applicable rules; proof of service is the record showing that service happened.
It is also different from legal notice, which is the broader concept of legally sufficient communication.
Practical example
A process server delivers a summons and complaint to a defendant’s authorized agent. The server then signs a proof of service stating the date, time, address, method, and name of the person served. The plaintiff files that proof with the court.
Related terms
Quick check
Service is the delivery step. Proof of service is the evidence or filing that documents the delivery step.