To complete a California proof of service form, choose POS-010 if you served a summons and complaint or POS-040 if you served documents in a case that is already open, then have the person who actually delivered the papers fill in the case caption, list every document served, identify who received them and how, and sign under penalty of perjury. The form is a sworn record, so every entry has to match the real service event exactly. A missing checkbox, a wrong date, or the wrong form number can invalidate the service and stall your case.
Pick the Right Form First
California uses two main Judicial Council forms, and using the wrong one is the most common early mistake. Form POS-010 proves service of a summons and complaint, the documents that start a lawsuit.1Judicial Branch of California. Proof of Service of Summons POS-010 Form POS-040 covers service of other civil documents filed after the case is underway, such as motions, discovery requests, and notices.2Judicial Branch of California. Proof of Service — Civil (Proof of Service) POS-040 File a POS-040 for a summons and the clerk will likely reject it.
Both forms are free fillable PDFs on the California Courts website, and any Superior Court clerk’s office has blank copies at the counter.3Judicial Council of California. POS-040 Proof of Service — Civil
Who Signs as the Server
The person who physically delivered the documents is the one who fills out and signs the form. That person must be at least 18 and cannot be a party to the case.4California Courts. Serving Court Papers You cannot serve your own papers. A friend, a relative, a coworker, a sheriff, or a registered process server can. If you hired a professional, confirm they are registered with the county clerk before you rely on their service.5California Legislative Information. California Code BPC 22350
Fill in the Header From the Filed Complaint
Both forms open with the same header block: plaintiff or petitioner, defendant or respondent, court name and address, and case number. Copy the caption character by character from the filed complaint or the other document you served. If a judge and department have been assigned, add them in the upper right. Small misspellings can separate the form from the case file, so treat the header as a transcription task, not a fresh entry.3Judicial Council of California. POS-040 Proof of Service — Civil
Working Through POS-040 Item by Item
The body of POS-040 has six numbered items. Each captures one piece of the service event, and the form works only when they all match what actually happened.
- Item 1, age declaration. The server checks the box confirming they are at least 18. If they were not, the service is invalid, regardless of what the form says.
- Item 2, server’s address. The server prints their home or business address.
- Item 3, fax number. Fill this in only if service was made by fax. Otherwise leave it blank.
- Item 4, documents served. List every document delivered. If the list is long, check the Item 4 box, complete attachment form POS-040(D), and staple it to the proof of service.
- Item 5, persons served. Give the name, address, and applicable information for each recipient. For multiple recipients, check the box and attach POS-040(P).
- Item 6, method of service. Check one box: personal delivery, mail, overnight delivery, messenger service, or fax. Only one method per form. If you served the same document on different people by different methods, use a separate POS-040 for each.
People sometimes second-guess Item 6 when they used substituted service, which involves both a physical delivery and a follow-up mailing. Those steps are parts of one method, not two, and they go on a single form.3Judicial Council of California. POS-040 Proof of Service — Civil
Extra Steps for Substituted Service
Substituted service takes more documentation than any other method. It becomes available only after the server has made reasonable efforts at personal delivery, typically at least three attempts on different days of the week and at different times of day.6California Courts. Serve Your Lawsuit by Substituted Service The server then leaves the documents with a competent adult at the person’s home, workplace, or usual mailing address, tells that person what the papers are about, and mails a copy to the defendant at the same address by first-class mail.7California Legislative Information. California Code of Civil Procedure CCP 415.20
The mailing is not optional. Substituted service is not complete without it, and service is deemed effective only 10 days after the mailing date. Skipping this step is one of the most frequent reasons substituted service gets thrown out.
Attach a Declaration of Due Diligence to the proof of service. The declaration describes every attempt at personal delivery: date, time of day, address, and result (for example, “no one answered the door” or “receptionist said defendant was out of the office”).6California Courts. Serve Your Lawsuit by Substituted Service The server signs it under penalty of perjury. There is no mandatory Judicial Council form for this declaration, though the general-purpose MC-030 works as a template.
Record who accepted the papers. If they gave their name, write it down. If they refused, the server writes a physical description in its place.
Recording Service on a Business or Entity
Serving a corporation, partnership, or unincorporated association means delivering to someone the law allows to accept service for the entity. For a corporation, that includes the designated agent for service of process listed with the Secretary of State, the president, CEO, vice president, secretary, treasurer, CFO, general manager, or anyone the corporation has authorized to accept service.8California Legislative Information. California Code CCP 416.10 For a partnership or unincorporated association, service can go to the designated agent, a general partner, the president or head of the organization, or a general manager.9California Legislative Information. California Code CCP 416.40
On the form, write both the name of the individual who received the papers and their title or capacity: “office manager,” “registered agent,” “vice president.” POS-010 specifically asks for this because the court has to confirm the papers reached someone authorized to accept them.10California Legislative Information. California Code of Civil Procedure CCP 417.10
Signing and Filing the Completed Form
Only the server signs, and only the server. Not the plaintiff, not the attorney, not a paralegal who wasn’t there. The declaration reads: “I declare under penalty of perjury under the laws of the State of California that the foregoing is true and correct.”11Legal Information Institute. California Code of Regulations Title 1 1008 The server prints their name below the signature and adds the date and city where they signed.
After the server signs, the party who arranged service files the original with the court clerk. Most Superior Courts accept electronic filing through approved vendors; some still require paper filing in person or by mail. Get a file-stamped copy back and keep it. If the other party later claims they were never served, that stamped copy is your answer.
Getting the Dates Right
The dates on the form drive the defendant’s response deadline, so accuracy matters. After personal service of a summons, the defendant has 30 days to file a response. After substituted service, service is deemed complete 10 days after the mailing step, and the 30-day clock starts from that point, which gives the defendant roughly 40 days from when the papers were left and mailed.7California Legislative Information. California Code of Civil Procedure CCP 415.20 Recording the delivery date, and the mailing date where applicable, is what lets the court and the parties calculate those deadlines. Note also that the California Rules of Court expect a plaintiff to serve the summons and complaint within 60 days of filing.
One boundary worth flagging: electronic service is only available for documents exchanged after a case is underway, not for the initial summons and complaint.12California Legislative Information. California Code CCP 1010.6 Service by mail with acknowledgment under CCP 415.30 is only complete if the recipient signs and returns the POS-015 acknowledgment; if they ignore it, you have to serve another way.13Judicial Council of California. POS-015 Notice and Acknowledgment of Receipt — Civil
Common Mistakes That Get Service Thrown Out
Defective service is one of the most common reasons civil cases stall. If the form is incomplete, the server was unqualified, or the method didn’t comply with the Code of Civil Procedure, the defendant can move to quash. A successful motion means the court treats the service as if it never happened, and the plaintiff starts over.
The mistakes that most often get service quashed are:
- Having a party to the case perform the service.
- Filing POS-040 for a summons that required POS-010, or vice versa.
- Checking more than one method box in Item 6.
- Skipping the required first-class mailing after substituted service.
- Filing without the Declaration of Due Diligence when substituted service was used.
- Recording the wrong address, wrong date, or wrong title for a business representative.
- Someone other than the actual server signing the form.
Read the completed form against the filed complaint and against the server’s own notes before it goes to the clerk. Double-checking every field is the cheapest insurance in litigation.