How to Fill Out California Form SC-100A: Other Plaintiffs or Defendants

California Form SC-100A, “Other Plaintiffs or Defendants,” is the one-page attachment you use to add parties to a small claims case when the main claim form runs out of room. The SC-100 (Plaintiff’s Claim) has space for only two plaintiffs and one defendant, so if you are suing two defendants, filing with three or more co-plaintiffs, or adding parties to a defendant’s counterclaim on SC-120, you fill out SC-100A and staple it to the main form.¹² Everything on it becomes part of the original filing, not a separate case.

When You Need to Attach SC-100A

Use SC-100A any time either side of your case has more parties than the main form holds. A landlord-plus-property-management-company suit is the classic trigger: two defendants, so one of them has to go on the attachment. A group of three friends suing over a shared deposit is another, because the SC-100 only has lines for two plaintiffs.¹

The attachment itself fits two more plaintiffs and two more defendants. If your case has still more parties than that, check the overflow box at the bottom of the relevant section and staple on another SC-100A.³

What to Gather Before You Fill It Out

For every party you plan to add, you need a full legal name, street address, mailing address if it differs, and a phone number. Get the name right. A judgment entered against a misspelled or vague party can be hard to enforce.³

If a defendant is a corporation, LLC, or public entity, the form asks you to name the person or agent authorized to accept service of process on that entity’s behalf.³ California businesses are required to designate one, and you can look it up through the Secretary of State’s bizfile Online search at bizfileonline.sos.ca.gov. Search by business name, and the filing record shows the registered agent and address.⁴

If a plaintiff you are adding does business under a fictitious business name (a DBA), SC-100A has no field for it. List the party’s actual legal name on SC-100A, then fill out and attach Form SC-103 (Fictitious Business Name Declaration) to link the DBA to that legal name for the court record.³⁵

Filling Out the Form Field by Field

Work through SC-100A in this order:

Header. Copy the case name onto SC-100A exactly as it appears on your SC-100 or SC-120. If the clerk has already assigned a case number, write it in; if you are filing everything for the first time, leave that box blank and let the clerk stamp it.
Additional plaintiffs. In the plaintiffs section, enter each extra plaintiff’s name, street address, city, state, ZIP, mailing address if different, and phone number.
Additional defendants. Do the same in the defendants section. For any corporate, LLC, or public entity defendant, fill in the line for the person or agent authorized for service of process.
Overflow box. If you have more than four plaintiffs or more than three defendants total across the SC-100 and this SC-100A, check the overflow box in the relevant section and attach another SC-100A.³
Signature. Sign and date at the bottom. The signature is a declaration under penalty of perjury that the information is true and correct.

Keep the numbering continuous with the main form. If SC-100 already lists Plaintiff 1 and Plaintiff 2, the first person on SC-100A is Plaintiff 3. That consistency helps the judge follow who is who during the hearing.³

Filing It With Your Main Claim

SC-100A is filed together with the SC-100 (or SC-120) as a single packet. There is no separate fee for the attachment; you pay only the filing fee for the underlying claim.⁶

Make copies before you go to the clerk. You need the original set for the court, one copy for yourself, and one copy for each defendant. Three defendants means four complete sets, and the SC-100A pages must be stapled into every set.⁵ You can take the packet to the clerk’s window, mail it in with a self-addressed stamped envelope so the clerk can return your stamped copies, or e-file if your local court accepts it.⁶

Serving Each Defendant You Added

Filing does not put anyone on notice. Each defendant listed on the SC-100A has to be served with a copy of the filed claim, SC-100A pages included, by someone at least 18 years old who is not a party to the case. You cannot serve the papers yourself.⁷

How far in advance of the hearing you need to serve depends on the method:⁸

Personal (hand) service: at least 15 days before the hearing if the defendant is in the same county, 20 days if out of county.
Certified mail by the clerk: the signed return receipt must come back at least 15 days before the hearing (20 out of county).
Substituted service, meaning papers left with a responsible adult at the home or business and a copy then mailed: at least 25 days in-county, 30 days out-of-county.

Your server fills out a Proof of Service for each defendant, and that proof has to be filed with the court at least five days before the hearing.⁸ With multiple defendants on SC-100A, every one of them needs their own proof. A single unserved defendant can get your case taken off the calendar.

Fixing a Name or Adding Another Party After Filing

If you catch a misspelling or realize you forgot someone before the claim has been served, don’t bother with an amendment form. File and serve a corrected SC-100 and SC-100A from scratch; the courts call that an amended claim. If the statute of limitations is still open, you can also dismiss and refile.⁹

If the claim has already been served, use Form SC-114 (Request to Amend Party Name Before Hearing). Mail or hand-deliver a copy to every other party and file the original with the court. The judge decides at the hearing whether to grant the change.⁹ Adding an entirely new defendant after service is harder than fixing a typo, because the new party has to be properly served and given time to prepare, which can push the hearing out.

Where to Get SC-100A

SC-100A is a fillable PDF on the California Courts self-help site at selfhelp.courts.ca.gov, listed on the small claims forms page with SC-100 and the rest of the standard small claims documents.¹⁰ Fill it in on a computer and print, or print a blank and complete it by hand.⁵ Clerk’s offices keep paper copies on hand if you’d rather pick one up.

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Judicial Council of California. SC-100 Plaintiff’s Claim and ORDER to Go to Small Claims Court
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Judicial Branch of California. Other Plaintiffs or Defendants
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Judicial Council of California. SC-100A Other Plaintiffs or Defendants
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California Secretary of State. bizfile Online Business Search
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California Courts. Fill Out Forms to Start a Small Claims Case
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California Courts. File Your Plaintiff’s Claim
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California Courts. Serve Your Small Claims Forms
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California Legislative Information. California Code of Civil Procedure 116.340
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California Courts. Request to Amend Party Name Before Hearing (Small Claims)
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California Courts. Small Claims Forms