FL-335 is the California Proof of Service by Mail form. Service requirements vary by situation, so always verify current rules and whether mail service is allowed for what you are filing.

What should I track when serving by mail?

Exactly what was served, the address used, the date mailed, and who did the mailing (often a non-party). Keep copies of what was sent and any mailing receipts if applicable.

Is this legal advice?

No. MyCustodyCoach is not a law firm and does not provide legal advice. This is educational guidance.

FL‑335 — Proof of Service by Mail Checklist

Proof of service mistakes can derail timelines. This page is a practical checklist for organizing mail service records and avoiding common errors. Educational only — not legal advice.

What to gather

Exact documents served (packet copy)
Mailing address used (and where it came from)
Mailing date and method details
Non-party server details (if required)

Common mistakes

Serving the wrong version of the packet
Using an outdated address
Missing the “who mailed it” requirement (when applicable)
Not filing proof of service on time

FL‑300 (Request for Order) — custody/visitation checklist
FL‑105/GC‑120 (UCCJEA) — custody jurisdiction checklist

Accuracy & sources

Last reviewed: 2026-01-15. This page is educational only — not legal advice.

Official sources

California Courts Self‑Help — FL‑335 (Proof of Service by Mail):
https://selfhelp.courts.ca.gov/jcc-form/FL-335

MyCustodyCoach is not a law firm and does not provide legal advice. Always verify current requirements (forms, fees, deadlines, service rules) with your local court or an attorney.

FL‑335 — Proof of Service by Mail Checklist

What to gather

Common mistakes

Related

Accuracy & sources

Official sources