California Form FL-335 is the Proof of Service by Mail document that proves you mailed family law papers to the other side, and you fill it out by entering case information, listing every document mailed, identifying the person served, stating the mailing address and date, and signing under penalty of perjury. The form is completed by an adult who is not a party to the case, who personally placed the documents in a sealed envelope with prepaid first-class postage and deposited them with the United States Postal Service.
Missing one box on this single-page form can void your service, push your hearing date back by months, and force you to refile motions you already paid for. According to the Judicial Council of California’s court statistics report, family law filings exceed 400,000 new cases each year, and improper service is one of the top procedural reasons judges deny Requests for Order at the first hearing.
Here is what you will learn in this guide:
- 📄 How to fill out every line of FL-335 without triggering a clerk rejection
- ⚖️ The exact statutes under California Code of Civil Procedure §§ 1013 and 1013a that govern mail service
- 🗓️ How mailing changes your filing deadlines under the 16 court days plus 5 calendar days rule
- 🚫 The seven most common mistakes that void proof of service and how to fix them
- 📬 Real, named examples covering divorce, custody, child support, and post-judgment motions
What Is California Form FL-335?
California Form FL-335 is the official Proof of Service by Mail used in family law cases statewide. The form is published and maintained by the Judicial Council of California, the rule-making body for the state’s trial courts. Anyone who serves family law documents by U.S. mail uses this form to swear, under penalty of perjury, that the mailing happened correctly.
The form lives inside the FL-series of family law forms, which covers divorce, legal separation, annulment, parentage, child support, spousal support, custody, visitation, and domestic violence matters. FL-335 is filed with the court clerk after service is complete, and the original is placed in the case file as proof that the other party received notice. Without a filed proof of service, the court treats the other side as if they were never told about the hearing or filing.
The plain-English purpose is simple. The form tells the judge, “I mailed these papers to the other parent on this date, at this address, and here is my signature swearing it is true.” The consequence of skipping or botching the form is severe, because under California Rules of Court Rule 1.21 a court will not act on documents that are not properly served and proven served.
For a quick example, imagine Maria files a Request for Order asking for child support. She mails the request to the father, but she fills out FL-335 and signs it herself. The clerk accepts the filing, but at the hearing the judge sees that Maria was a party who served her own papers, which is not allowed, and continues the hearing for 60 days. A common misconception is that any adult, including the filing party, can sign the proof. That is false, and it is the single most frequent reason these forms get tossed.
When Do You Use Form FL-335?
You use FL-335 any time you serve another party with family law papers by U.S. mail and you need to document that service for the court. The form is not used for personal service, which requires Form FL-330 instead. It is also not the right choice for the very first papers in a divorce, because original Summons and Petition documents must be personally served under Code of Civil Procedure § 415.10.
Common Family Law Filings That Use FL-335
Mail service with FL-335 is the standard method for a wide range of post-Petition filings. These include Requests for Order, Responsive Declarations, Income and Expense Declarations, Schedules of Assets and Debts, settlement proposals, and most discovery responses. After the initial Summons is served, almost every later document in the case can travel by mail.
Post-judgment filings also use this form. Motions to modify child support, requests to change custody, and notices of contempt hearings can all be served by mail once the responding party has appeared in the case. The reason post-judgment service usually works by mail is that the court already has personal jurisdiction over both parties, so the strict personal-service rule has been satisfied earlier in the case.
A real example helps clarify timing. James, a father in Sacramento, files an RFO to lower his child support after losing his job. Because his ex-wife already responded to the original divorce, James can mail the RFO and FL-335 instead of hiring a process server. He saves about 95 dollars in service fees, which is the typical cost charged by California-registered process servers.
Filings That Cannot Use FL-335
Initial process documents demand personal service, not mail. The original Petition (FL-100), Summons (FL-110), and any Domestic Violence Restraining Order request under Family Code § 6300 require hand delivery to the responding party. The consequence of mailing these is a complete failure of service, meaning the case cannot move forward and any default judgment can be set aside later.
Out-of-country service has its own rules under the Hague Service Convention, which generally cannot be satisfied by ordinary U.S. mail. A misconception is that mailing internationally always works because postage stamps are still valid abroad. That is wrong, and the U.S. State Department warns that mail service to Hague-signatory countries can be rejected outright by foreign courts.
Step-by-Step: How to Fill Out FL-335
The form has a header section and six numbered paragraphs. Each section asks for a different piece of information, and every box matters. The full official instructions are linked on the California Courts FL-335 form page.
Caption Block: Attorney, Party, and Court Information
The top-left caption asks for the name, address, and phone number of the attorney or self-represented party who is filing the underlying document. If you are the petitioner without a lawyer, write your own name, mailing address, and a phone number where the court can reach you. The State Bar number line stays blank for non-attorneys.
The top-right caption is for the clerk’s filing stamp, so leave that area empty. Below the caption you list the Superior Court of California county, the court’s street address, the mailing address if different, the city and zip code, and the branch name. Each of these fields must match exactly what appears on your original Petition, because mismatched courts can confuse the clerk and delay file acceptance.
A scenario helps make this concrete. Aisha files in Los Angeles County’s Stanley Mosk Courthouse, but she writes “Los Angeles Superior Court” with no branch name on her FL-335. The clerk’s office stamps it in, but her papers later get routed to the wrong courthouse for hearing. The consequence is a one-week delay while the file is transferred, which can push her urgent custody hearing past a school enrollment deadline.
Case Name and Case Number
The case name lists the petitioner first and the respondent second, exactly as printed on the original Petition. Write In re the Marriage of [Last Name] and [Last Name] for divorce cases, or [Petitioner] v. [Respondent] for parentage cases. Using nicknames or abbreviated names triggers clerk rejections under local filing rules.
The case number must match the number assigned at the original filing. Copy it character-for-character from your conformed Petition, including any letters or hyphens. A wrong digit means the proof gets filed in someone else’s case, which is both a privacy violation and a service failure.
Paragraph 1: Server Eligibility Statement
Paragraph 1 is a pre-printed statement that says the server is at least 18 years old and not a party to the case. You do not write anything here, but you must make sure both facts are true before signing the form at the bottom. The rule comes from Code of Civil Procedure § 1013a(1), which bars parties from serving their own papers.
The consequence of having a party sign is automatic invalidation of service. Even a 17-year-old neighbor signing the form is enough to wipe out the proof, because minors cannot serve process. A common misconception is that a spouse who has not yet responded counts as a “non-party” because they have not appeared. That is incorrect, because the moment a Petition names someone as Respondent, that person is a party.
For example, David asks his 19-year-old roommate Tom to drop the envelope at the post office. Tom is the proper server because he is over 18 and unrelated to the case. David must give Tom the form to sign personally, not sign it himself even though he watched Tom mail it.
Paragraph 2: Residence or Business Address of Server
Paragraph 2 asks where the server lives or works. Write the full street address, city, state, and zip code in this box. A P.O. Box alone is not enough, because the court needs a physical location in case the server has to testify about the mailing.
The address links the server to a real, verifiable location. If service is later challenged, the court or opposing counsel can subpoena the server to a hearing, and the address tells them where to send the subpoena. Leaving this blank or writing only a city name is grounds for the clerk to reject the filing on sight.
Paragraph 3: Document List
Paragraph 3 is the heart of the form. List every document that was placed inside the mailed envelope, using the exact title that appears on each document. For example, write Request for Order (FL-300), Income and Expense Declaration (FL-150), and Declaration in Support of Request for Order.
If you ran out of space on the form, attach a separate page titled Attachment 3 and reference it in the box. Every attachment must be stapled to the original FL-335 before filing, because loose pages get separated by the clerk and can be lost. The consequence of omitting even one document from the list is that the omitted document is treated as never served, which can void an entire motion if a key declaration was left off.
A real-world example shows the stakes. Linda mails an RFO with a supporting declaration and exhibits, but on FL-335 she lists only the RFO. At the hearing, the judge looks at the file, sees no proof that the declaration was served, and refuses to consider any of Linda’s evidence. The whole hearing collapses into a continuance.
Paragraph 4: Person Served, Address, and Mailing Date
Paragraph 4 has three sub-boxes. Box 4(a) is the name of the person served, written exactly as it appears in the case caption. Box 4(b) is the complete mailing address used on the envelope, including any apartment number, city, state, and zip code. Box 4(c) is the date the envelope was placed in the mail.
The mailing address must be the most current address you have for the other party. If the other party is represented by an attorney who has appeared in the case, you must mail to the attorney’s office instead, under Code of Civil Procedure § 1015. Mailing directly to a represented party rather than to their lawyer is a procedural error that can void service entirely.
The mailing date is also the date that starts the clock for the other side’s response. Under Code of Civil Procedure § 1013(a), mailing inside California adds five extra calendar days to any response deadline. Mailing to an out-of-state address adds 10 days, and mailing to a foreign country adds 20 days, so the date in 4(c) is not just paperwork — it changes the timeline of the entire case.
Paragraph 5: Place and Date of Mailing
Paragraph 5 asks where you deposited the envelope and on what date. Write the city and state where you placed it in a U.S. Postal Service mailbox, post office, or office mail system that collects outgoing mail daily. The date here should match Box 4(c) exactly, because any difference between the two dates suggests the form was filled out sloppily and can prompt the judge to question authenticity.
The form gives two checkbox options. Option (1) covers personal deposit at a post office or mailbox, and Option (2) covers placement in a workplace mail system that follows ordinary business practices for outgoing mail. Choose only one, because checking both is internally contradictory and a clerk may flag the form.
Signature, Print Name, and Date
The bottom of the form has a date line, a printed-name line, and a signature line. The server signs in blue or black ink, prints their full legal name, and dates the form on the day they sign. Electronic signatures are allowed for efiling under California Rules of Court Rule 2.257, but a wet-ink original is safer if you plan to walk the form into the clerk’s window.
The signature is made under penalty of perjury, which means lying on the form is a crime under Penal Code § 118. The consequence of a false statement, such as backdating the mailing, can include perjury charges and contempt sanctions, in addition to having the underlying motion thrown out.
Three Common Service Scenarios
The same form is used in many different fact patterns, and the rules shift slightly with each one. The three scenarios below illustrate how the form interacts with deadlines, jurisdiction, and representation.
Scenario 1: Mailing an RFO to a Self-Represented Spouse in California
| What You Do | What the Court Does |
|---|---|
| Mail RFO and FL-150 to spouse’s California home address on June 1 | Hearing must be set at least 16 court days plus 5 calendar days after June 1 |
| File FL-335 with the clerk the same week | Clerk confirms service is timely and keeps the original RFO hearing date |
| Bring extra copies to the hearing | Judge proceeds on the merits because proof is in the file |
Scenario 2: Serving an Attorney of Record by Mail
| What You Do | What the Court Does |
|---|---|
| Mail papers to the attorney’s office address listed on prior filings | Treats service on the lawyer as service on the party under § 1015 |
| List the attorney’s name in Box 4(a) and the firm address in Box 4(b) | Accepts proof and applies normal mail-extension days |
| Skip the personal home address of the represented party | Ignores any later argument that the party did not personally receive notice |
Scenario 3: Mailing to an Out-of-State Parent in a Custody Modification
| What You Do | What the Court Does |
|---|---|
| Mail the modification request to the parent’s Texas address on July 10 | Adds 10 calendar days to the response deadline under § 1013(a) |
| List the full Texas address in Box 4(b) | Accepts the proof if the UCCJEA gives California jurisdiction |
| File FL-335 promptly with the California court | Sets the hearing date with the extended deadline already calculated |
Three Named Examples
Real people make abstract rules click. The three examples below show how FL-335 plays out in everyday family law work.
Maria, a mother in San Diego, files an RFO seeking emergency move-away orders. Her sister Elena, age 32, mails the papers from a downtown San Diego post office and signs FL-335 the same afternoon. Because Elena is over 18 and not a party, the proof is valid, and Maria’s hearing proceeds on the originally scheduled date.
James, a father in Fresno, wants to lower his child support after a layoff. He gives the documents to a paid registered process server, who mails them to the mother’s last known address and signs the FL-335. The process server’s bonded status under Business and Professions Code § 22350 gives James extra credibility if the mother later claims she never received the envelope.
Aisha, a respondent in Alameda County, mails a Responsive Declaration and FL-150 to the petitioner’s attorney. She lists the law firm in Box 4(b) and writes the attorney’s name in Box 4(a). The court treats the firm’s mailroom date stamp as conclusive proof that the attorney received notice, and Aisha’s response is deemed timely.
Mistakes to Avoid
Even careful people slip on this form, and the cost can be a continued hearing, a denied motion, or a sanctions order. Watch for the seven errors below.
- Signing the form yourself as a party. Service is void under § 1013a, and the court will continue the hearing.
- Forgetting to list every document in Paragraph 3. Any document left off is treated as never served, which can gut your evidence.
- Using an outdated address in Box 4(b). Mail returned as undeliverable means no notice, and the judge will not act.
- Mismatching the dates in Paragraphs 4(c) and 5. Inconsistent dates invite a perjury concern and can void the proof.
- Mailing directly to a represented party. This violates § 1015 and the attorney can move to strike the filing.
- Filing a photocopy with a copied signature. Some clerks reject non-original signatures unless e-filed under Rule 2.257.
- Missing the 16-court-day window. Under § 1005, late mailing means the hearing cannot proceed on the noticed date.
Do’s and Don’ts of Mail Service
Following the right habits keeps your filings clean and your hearings on track. Skipping them invites delay and judicial frustration.
Do’s
- Do use first-class postage with full prepaid postage, because § 1013a(1) requires it.
- Do keep a copy of the sealed envelope’s label, since photo evidence can rebut a “never received” claim.
- Do confirm the responding party’s most recent address through the California Department of Motor Vehicles records request when in doubt.
- Do mail early in the week, because Saturday and Sunday do not count as mailing days for some deadline rules.
- Do staple all attachments together before filing, so the clerk does not lose loose pages.
Don’ts
- Don’t let a minor sign the form, because § 1013a bars under-18 servers.
- Don’t mail Domestic Violence restraining order papers, since Family Code § 243 requires personal service.
- Don’t backdate the mailing date, because perjury under Penal Code § 118 carries felony exposure.
- Don’t rely on certified mail alone for the first Summons, since personal service is still required.
- Don’t assume your hearing date stays put if you mail late, because the court will continue it on its own motion.
Pros and Cons of Mail Service With FL-335
Mail service is fast and cheap, but it is not the right tool for every situation. Weigh the trade-offs before choosing it over personal service.
Pros
- Lower cost, because USPS first-class postage is far cheaper than a process server’s 95-to-150-dollar fee.
- Faster turnaround, since you can mail the same day you finalize the documents.
- Simple paperwork, because FL-335 is a single page once filled out correctly.
- Wide applicability, since most post-appearance family law documents qualify under § 1013.
- Easy to repeat, when serving multiple sets of papers in the same case.
Cons
- No delivery confirmation, because first-class mail does not provide tracking unless you pay extra.
- Extra response time, since § 1013 adds 5, 10, or 20 days to the other party’s deadline.
- Address risk, because a stale address means the recipient never sees the papers.
- Not allowed for initial process, so the original Petition still needs personal service.
- Easier to challenge, since opposing counsel can argue non-receipt more credibly than with a process server’s affidavit.
Filing the Completed FL-335 With the Court
Once the form is signed, file the original with the clerk in the same county where the underlying case is pending. Filing methods vary by county, and many courts now require electronic filing through portals like Odyssey eFileCA or One Legal. Walk-in filing is still allowed in most counties, and there is no filing fee for a proof of service.
The clerk stamps the form with a date and places it in the case file. Keep a conformed copy for your own records, because it may be needed at the hearing or in any future appeal. Lost proofs of service can be reconstructed under Code of Civil Procedure § 1013b, which now allows electronic verification, but starting from scratch wastes time.
A misconception is that filing the proof too late is harmless if service itself was on time. That is partly wrong, because some local rules require the proof to be on file at least five court days before the hearing. The consequence is that the bench officer may continue the hearing even though service was technically valid.
How Mail Service Affects Deadlines
Mail service does not just prove notice — it changes the timing of everything that follows. The default rule under Code of Civil Procedure § 1005(b) is that motion papers must be served and filed at least 16 court days before the hearing. When you mail inside California, you add 5 calendar days to that window, meaning you actually need to mail at least 16 court days plus 5 calendar days before the hearing.
Out-of-state mailing adds 10 days, and out-of-country mailing adds 20. The reason is that the legislature presumes mail takes longer to cross state lines or oceans, and the recipient deserves a fair window to respond. Missing this window is the single most common reason judges continue family law hearings on their own motion.
For example, if a hearing is scheduled for August 20 and you are mailing within California, count back 16 court days to roughly July 28, then add 5 more calendar days, landing on July 23 as the latest mailing date. A common misconception is that “court days” and “calendar days” can be combined into one count. They cannot, because court days exclude weekends and judicial holidays under Government Code § 6700.
Key Court Rulings on Mail Service
California appellate courts have repeatedly explained how strict the proof-of-service rules are. In Lee v. Placer Title Co. (1994) 28 Cal.App.4th 503, the court held that the presumption of receipt under Evidence Code § 641 applies only when proof of correct mailing is in the record. Without a clean FL-335 or its civil equivalent, the presumption disappears and the moving party must prove receipt by other means.
In Sharp v. Union Pacific R.R. Co. (1992) 8 Cal.App.4th 357, the court emphasized that even minor defects in proof of service can be fatal when due-process rights are on the line. The decision reinforces that judges have the discretion — and sometimes the duty — to refuse to act on motions where the proof of service is internally inconsistent or incomplete.
A misconception is that an opposing party who shows up at the hearing has waived any service objection. That is not always true, because California recognizes the right to make a special appearance under Code of Civil Procedure § 418.10 to challenge service without submitting to jurisdiction.
FL-335 vs. Related Proof of Service Forms
| Form | Use Case |
|---|---|
| FL-335 | Mail service in family law cases after the initial Petition |
| FL-330 | Personal service in family law cases, including initial Summons |
| POS-030 | Mail service in general civil cases, not family law |
| POS-040 | Personal service in general civil cases |
| FL-435 | Proof of service for earnings assignment orders for support |
Family law forms and civil forms cannot be swapped. Filing a POS-030 in a divorce case is a clerk-rejection trigger in many counties, because local rules under California Rules of Court Rule 5.2 require the FL-series forms in family law matters.
Federal Comparison: FRCP Rule 5
For context, federal courts handle proof of service under Federal Rule of Civil Procedure 5. Federal mail service is similar in spirit to California’s rule, requiring a non-party adult and a written certificate. Federal practice does not, however, use the FL-series forms, and family law matters are generally handled in state court because federal courts lack subject-matter jurisdiction over divorce under the domestic relations exception.
FAQs
Can I sign FL-335 myself if I am the petitioner?
No. Code of Civil Procedure § 1013a bars any party from serving their own papers, so a non-party adult must mail the documents and sign the form on your behalf.
Does FL-335 work for serving the original divorce Petition?
No. The original Summons and Petition require personal service under § 415.10, so you must use FL-330 with a process server or eligible non-party adult instead of FL-335.
Is mailing to my spouse’s lawyer acceptable instead of mailing to my spouse?
Yes. Once an attorney has appeared in the case, § 1015 requires service on the attorney rather than on the represented party, and FL-335 should list the firm’s address.
Do I add extra days to the response deadline when serving by mail?
Yes. Section 1013 adds 5 calendar days for in-state mailing, 10 days for out-of-state, and 20 days for out-of-country recipients before the response clock expires.
Can a 17-year-old neighbor mail my papers and sign FL-335?
No. The form’s pre-printed certification requires the server to be at least 18 years old, and a minor’s signature voids the proof of service entirely.
Is FL-335 the right form for serving a domestic violence restraining order request?
No. Restraining order papers under Family Code § 243 demand personal service, and mailing them with FL-335 leaves the protected party without enforceable notice.
Can I e-file FL-335 in California family law cases?
Yes. Most counties accept electronic filing through approved vendors, and electronic signatures comply with California Rules of Court Rule 2.257 if the original is retained.
Will the court reject my FL-335 if I forget the case number?
Yes. Clerks routinely reject filings that lack a matching case number because the document cannot be routed to the correct case file without it.
Is certified mail required for FL-335 to be valid?
No. First-class mail with prepaid postage satisfies § 1013a, although certified mail or tracked services can provide added proof if the recipient later denies receipt.
Can I correct a mistake on a filed FL-335 by submitting a new one?
Yes. You can file an amended proof of service, and many counties allow a corrected FL-335 to relate back to the original mailing date if the underlying mailing was timely.
Does FL-335 cover service on a child’s attorney appointed under Family Code § 3150?
Yes. A minor’s counsel is treated like any other attorney of record, so mailing pleadings to that attorney’s office and listing the address on FL-335 is proper.
Will mailing to a P.O. Box satisfy the address requirement in Box 4(b)?
Yes. A P.O. Box is acceptable for the recipient’s address if that is where they receive mail, but the server’s address in Paragraph 2 must be a physical street address.
Related reading
- How to Fill Out California Form FL-117 (w/Examples) + FAQs
- How to Fill Out California Form FL-320 (w/Examples) + FAQs
- How to Fill Out California Form FL-341 (w/Examples) + FAQs
- How to Fill Out California Form POS-020 (w/Examples) + FAQs
- How to Fill Out California Form POS-030 (w/Examples) + FAQs
- How to Fill Out California Form POS-050 (w/Examples) + FAQs
- How to Fill Out California Form CIV-010 (w/Examples) + FAQs