Service of Process · Updated October 2026

Substitute Service of Process in California

When the papers can’t be handed to the defendant, substituted service lets the server leave them with another adult and mail a copy. What each step requires, now and after January 1, 2027.

Direct Legal Blog

Service of Process

First published 2013 · Updated October 2026

Most defendants who can’t be handed the papers can still be served. Substituted service under CCP § 415.20, which most people call substitute service, lets the server leave the summons and complaint with another adult and then mail a copy. It’s also one of the most common reasons a default gets set aside, because each step has its own requirement and a gap in any one of them can undo the service. And the rules for individuals change on January 1, 2027.

Start here

Two Routes: Individuals and Businesses

Section 415.20 has two different versions of substituted service, and which one applies depends on who is being served.

Businesses and other entities (§ 415.20(a)). For a corporation, partnership, public entity, or other defendant served through a person listed in CCP §§ 416.10 to 416.50, the server can leave the papers during usual office hours at that person’s office with whoever is apparently in charge, then mail a copy. If no physical address is known, the papers can be left at the usual mailing address (not a USPS post office box) with an adult who is told what they are. There is no requirement to try personal delivery first.
Individuals (§ 415.20(b)). For a person served as an individual, substituted service is available only after personal delivery can’t be made with reasonable diligence. Then the papers can be left at the defendant’s home, usual place of business, or usual mailing address, followed by a mailing.

Get this right first, because it decides everything else in the assignment. For business defendants, our article on serving a registered agent covers who can accept and where.

Before you substitute

Reasonable Diligence Now, and After January 1, 2027

Through December 31, 2026, the statute requires reasonable diligence but doesn’t set a number of attempts. Courts have generally treated two or three good attempts at a proper address as enough (Espindola v. Nunez (1988) 199 Cal.App.3d 1389). Three visits at 10 a.m. on weekdays to a house where the defendant works days won’t look like much effort, so vary the times and include an evening or weekend.

Starting January 1, 2027, AB 747 writes the standard into the statute. For an individual, reasonable diligence means attempting personal delivery in good faith on at least three occasions, on three different days, at three different times (§ 415.20(b)(2)). In a consumer debt case, at least one attempt has to be at the defendant’s home if that address is known or could be found with reasonable effort (§ 415.20(b)(3)).

Two things the new rule doesn’t do. It doesn’t require three attempts before personal delivery; if the defendant answers the door on the first try, that’s complete service. And it doesn’t require three attempts at every address you know of. It requires at least three good-faith attempts at personal delivery before the papers are left with someone else.

Either way, the attempts belong in a declaration of diligence attached to the proof of service, with the date, time, address, and result of each one. Form POS-010 has a box for it, and the Judicial Council approved a new optional form for 2027, the Declaration of Diligence (POS-012), with a separate item for each attempt.

Where and with whom

The Right Place and the Right Person

For an individual, the papers have to be left at the defendant’s dwelling house, usual place of abode, usual place of business, or usual mailing address. A USPS post office box never qualifies. If the only address you can reasonably find is a private mailbox at a commercial mail receiving agency, such as a UPS Store, the papers can be left with the mail store on the first attempt (§ 415.20(c)).

The person who takes the papers has to be at least 18, has to be a competent member of the household or a person apparently in charge of the office, business, or mailing address, and has to be told what the papers are. Being an adult who happened to be at the address isn’t enough. The proof should name the person, or describe them if they won’t give a name, and say how they’re connected to the defendant or the address.

Gated communities and guarded buildings are a common problem. When a guard keeps refusing access, a court has upheld leaving the papers with the guard (Bein v. Brechtel-Jochim Group, Inc. (1992) 6 Cal.App.4th 1387). Our article on defendants avoiding service covers that and other hard cases. If the defendant answers but refuses the papers, that’s a different situation; see drop service.

Finishing the service

The Mailing, and When Service Is Complete

Leaving the papers is only half of substituted service. A copy of the summons and complaint then has to be mailed to the defendant at the address where the papers were left. Today that means first-class mail, postage prepaid. Starting in 2027, Priority Mail with tracking and Certified Mail with a return receipt are also allowed.

Service is complete on the 10th day after the mailing, not on the day the papers were left. The defendant then has 30 days to respond to a civil complaint (CCP § 412.20(a)(3)), so the response is due 40 days after the mailing. In an unlawful detainer, the response time is 10 days not counting weekends and court holidays. Make sure the proof shows the mailing date and address, and calculate both dates yourself.

New in 2027

Photos Starting January 1, 2027

For substituted service on or after January 1, 2027, the proof of service has to include photos of the site of each attempt and of the service itself (CCP § 417.10). That includes the attempts the diligence declaration relies on:

each photo carries an automatic stamp with the date, time, and GPS or equivalent coordinates, taken as close as practicable to the attempt or service
the photo shows the door of the home or the specific office, or the entrance with a specific explanation if the door isn’t reasonably accessible
a detailed statement covers any photo without a readable location stamp because there was no signal
if a photo would have put the server at risk, the server documents the service or attempt and the reason, on or with the proof (AB 2042)

No photo of the person served is required. Our article on the 2027 service changes has the details, including the new rules for challenging a default.

Before you rely on it

Before You Rely on Substituted Service

The defendant was served the right way for what it is: an individual under § 415.20(b), a business under § 415.20(a).
For an individual, the attempts show reasonable diligence, and from 2027 meet the three-day, three-time rule (with a home attempt in a consumer debt case).
The address is a home, usual place of business, or usual mailing address, and not a USPS post office box.
The person who took the papers is named or described, was at least 18, and was told what the papers were.
The mailing went to the same address, and the proof shows the date.
You calculated the completion date (10 days after mailing) and the response deadline.
For 2027 service, the photos and any exception statements are attached.

Every Direct Legal process serving order in California includes up to 4 to 6 attempts at a single address, made at different times of day. When we serve by substituted service, we handle the mailing and include a declaration of diligence with the signed proof of service.

Please note

About This Article

This article is general information about California law and court procedure as of October 2026. It is not legal advice, and reading it does not create an attorney-client relationship. Direct Legal Support is a registered process serving and litigation support company, not a law firm. Statutes, court rules, and forms change, so check the current versions and your court’s local rules, and talk with an attorney about your specific matter.