Proof of Service in California: POS-010, POS-040, and When Each Applies

Service that isn't documented might as well not have happened: the proof of service is what the court file actually contains. California's Judicial Council publishes standardized proof of service forms, and the two civil workhorses are POS-010 and POS-040. They are not interchangeable — each covers a different kind of service, and POS-040 says on its face not to use it for the other one's job. Here is which form fits which situation, and what each one actually asks.

The short version

POS-010, Proof of Service of Summons — for proving service of the summons (with the complaint and its companion documents). It is a mandatory-use form, and its own citation is Code of Civil Procedure section 417.10, the statute governing proof of service of summons.
POS-040, Proof of Service—Civil — for proving service of other case documents (motions, notices, discovery responses served conventionally, and the like) by personal delivery, mail, overnight delivery, messenger, or fax. It is an optional-use form, citing Code of Civil Procedure sections 1011, 1013, 1013a and 2015.5, and rule 2.306 of the California Rules of Court.

POS-040's instructions draw both boundaries explicitly: it should not be used to show service of a summons and complaint — that is POS-010's job — and it should not be used for electronic service, which has its own form, POS-050, Proof of Electronic Service.

POS-010: proving service of a summons

POS-010 is the form the person who served the summons completes — and the form itself states that a separate proof of service is required for each party served. Its structure follows the serve:

Who served. The server declares they were at least 18 years old and not a party to the action, and later (item 7) gives their name, address, telephone number, the fee charged for service, and their registration status — not registered, exempt from registration under Business and Professions Code section 22350(b), or a registered California process server with registration number and county.
What was served (item 2): summons, complaint, Alternative Dispute Resolution package, Civil Case Cover Sheet (in complex cases), cross-complaint, or other specified documents.
Who was served and where (items 3–4): the party as named on the documents, any person served on the party's behalf, and the address.
How (item 5) — one of four methods:
- Personal service, with date and time;
- Substituted service, with date, time, and the person left with — at a business, a home, or (where no physical address is known) a usual mailing address — plus the follow-up first-class mailing the statute requires, and, for individuals, an attached declaration of diligence describing the attempts at personal service that came first (we walk through those requirements in our guide to CCP §415.20);
- Mail with acknowledgment of receipt under section 415.30 — including, for out-of-state addresses, mail with return receipt requested under section 415.40; or
- Other means authorized by a code section the server must specify.
In what capacity (item 6): how the "Notice to the Person Served" on the summons was completed — as an individual defendant, as a fictitiously named defendant, as occupant, or on behalf of an entity under a listed statute: 416.10 (corporation), 416.20 (defunct corporation), 416.30 (joint stock company/association), 416.40 (association or partnership), 416.50 (public entity), 415.95 (business organization, form unknown), 416.60 (minor), 416.70 (ward or conservatee), 416.90 (authorized person), or 415.46 (occupant).
The declaration. The server signs under penalty of perjury under California law — or, if the server is a California sheriff or marshal, certifies the contents instead.

POS-040: proving service of everything else (served conventionally)

Once a case is underway, the papers that move between the parties — motion papers, notices, conventional discovery service — get proved on POS-040 when served by traditional means. The form covers five methods, and the server checks exactly one per form: personal service, mail, overnight delivery, messenger service, or fax. Its instructions are specific: if you served a party by several methods, use a separate form for each method.

Details worth knowing before filling it out:

The server declares they were over 18 and not a party to the action — on POS-040's own instructions, a party cannot be the one who serves the documents.
Mail service offers two declarations: the envelope was deposited with the U.S. Postal Service with postage fully prepaid, or it was placed for collection and mailing under the business's ordinary practices — the standard office-mailroom declaration, matching the practice described in section 1013a.
Messenger service requires a declaration from the messenger — either the Declaration of Messenger printed on the form or a separate one attached.
Fax service rests on the parties' agreement to accept service by fax, and the transmission record is attached.
Long lists have attachments: additional documents go on form POS-040(D), additional persons served on form POS-040(P).
Like POS-010, it is signed under penalty of perjury.

Choosing in practice

Ask two questions. First: is a summons being served? If yes, it is POS-010, one per party served. Second: how was the document served? Personal, mail, overnight, messenger, or fax — POS-040. Electronic service — POS-050, not POS-040. And some documents must be served in a particular manner regardless of convenience — POS-040's own information sheet gives the example that an order to show cause and temporary restraining order generally must be personally delivered — so the method, not just the form, has to fit the document.

Where the proof comes from

A proof of service is only as good as the field record behind it. When Legal Hub Group's process servers complete a serve, the proof of service is generated from the server's own attempt record — dates, times, addresses, and the manner of service, GPS-verified — rather than reconstructed from memory at filing time. The completed proof is ready to file through our e-filing service under the court's proof of service filing code, which closes the loop: serve, prove, file.

This is general information, not legal advice.