Served With a Cross-Complaint in California: Deadlines and Strategy

Last updated: October 2026

A cross-complaint is a lawsuit inside a lawsuit. If you have been served with one in California, you have 30 days to move, demur, or otherwise respond, the same as with an original complaint. (Code Civ. Proc., § 432.10.) Kolmogorov Law, P.C. represents businesses and owners on both ends of cross-complaints in Orange County, Los Angeles, and across California: defending them, and filing them when a defendant has claims of its own.

Call (909) 235-6116 or contact us online to discuss a cross-complaint you have been served with or need to file.

What a cross-complaint is

When a defendant is sued, it often has claims of its own. Some are against the plaintiff. Some are against a third party who is really responsible, such as a subcontractor, a co-owner, or an insurer. In California those claims are pleaded in a cross-complaint, filed in the same case. The defendant becomes a cross-complainant, and the person it sues becomes a cross-defendant.

The practical effect is that one lawsuit now runs in two directions. A vendor sues a distributor for unpaid invoices; the distributor cross-complains for defective product. A departing partner sues for his share; the company cross-complains for the money he moved out before he left. Every month I see cases where the cross-complaint ends up being the larger claim.

The 30-day clock

The rule is short. A party served with a cross-complaint may, within 30 days after service, move, demur, or otherwise plead to it in the same manner as to an original complaint. (Code Civ. Proc., § 432.10.) The deadline runs from service, and how you were served affects the count, so the first thing we do is pin down the service date and method. Our court date calculator handles the court-day arithmetic.

Missing the deadline exposes you to a default on the cross-complaint, even if you are actively litigating the main case. That happens more often than it should, usually because the cross-complaint arrived in a stack of other papers.

Compulsory cross-complaints: use it or lose it

California forces certain claims into the case. If you are sued and have a related cause of action against the plaintiff when you serve your answer, you must plead it in a cross-complaint. Otherwise you lose the right to bring it later in any other action. (Code Civ. Proc., § 426.30, subd. (a).) The bar does not apply if the court lacks personal jurisdiction over you or if you never filed an answer. (Code Civ. Proc., § 426.30, subd. (b).)

This is the rule that catches business owners who decide to "deal with our claims later." A claim that arises from the same transaction as the plaintiff's claim usually counts as related. If it is not pleaded now, it is gone.

Claims against people who are not already plaintiffs are permissive. You may bring them in the same case or in a separate action, and the choice is strategic.

When a cross-complaint can be filed

A cross-complaint against a party who sued you must be filed before or at the same time as your answer. (Code Civ. Proc., § 428.50, subd. (a).) Any other cross-complaint may be filed at any time before the court sets a trial date. (Code Civ. Proc., § 428.50, subd. (b).) Outside those windows you need leave of court, which may be granted in the interest of justice at any time during the action. (Code Civ. Proc., § 428.50, subd. (c).)

Leave is usually granted when the request is prompt and the new claims are tied to the existing case. It gets harder as trial approaches and the other side can show prejudice.

Your options when you are the cross-defendant

You have the same menu you would have for a complaint. An answer denies the allegations and raises affirmative defenses. A demurrer tests whether the cross-complaint states a claim at all, and it requires a meet-and-confer conference before filing. (Code Civ. Proc., § 430.41, subd. (a).) A motion to strike targets improper matter, such as punitive damages allegations with no supporting facts. Our demurrer page explains when each tool is worth the money.

Two other steps belong in the first week. Tender the cross-complaint to your insurers; a cross-complaint alleging negligence or property damage may trigger a defense obligation that the original complaint did not. And check for an arbitration clause in whatever contract the cross-complaint is based on, because a petition to compel arbitration is often due with your first response.

How a cross-complaint changes the case

Settlement math changes the moment a cross-complaint is on file. A plaintiff who expected a one-way claim now has exposure of its own, and a contractual fee clause runs in both directions under Civil Code section 1717. Discovery broadens. Trial gets longer. All of that favors the party with the stronger cross-claim and costs everyone else, which is why we look hard at whether a cross-complaint is worth filing before we recommend one.

Where these cases are heard

Cross-complaints are filed in the court where the original case is pending. For most of our clients that means the Orange County Superior Court Central Justice Center in Santa Ana or the Stanley Mosk Courthouse in Los Angeles. In federal cases the equivalent pleadings are counterclaims and third-party complaints under the federal rules, with their own timing.

What to bring to the first meeting

Bring the cross-complaint, the proof of service, the original complaint and your answer if one was filed, the contracts the claims are based on, and your insurance policies. If you think you have claims of your own against the plaintiff or anyone else, write them down now; the compulsory rule means they may have to be filed with your answer.

Frequently asked questions

How long do I have to respond to a cross-complaint in California?

Thirty days after service. (Code Civ. Proc., § 432.10.) The response can be an answer, a demurrer, a motion to strike, or a motion to quash, and some of those have their own prerequisites, so start early.

What happens if I do not respond to a cross-complaint?

The cross-complainant can request entry of your default on the cross-complaint, even though you are defending the main case. Getting a default set aside is possible but costs time and money. Respond on time.

Do I have to file my own claims as a cross-complaint?

If your claim is against the plaintiff and is related to the plaintiff's claim, yes. A related claim not pleaded in a cross-complaint when you serve your answer is barred in any later action. (Code Civ. Proc., § 426.30, subd. (a).) Claims against other people are optional.

Can I file a cross-complaint after I have already answered?

Against the plaintiff, you will need leave of court. Against other parties, you may file without leave until the court sets a trial date. (Code Civ. Proc., § 428.50.) Courts generally grant leave when the request is timely and the claims are connected to the case.

Does my insurance cover a cross-complaint?

Sometimes. Coverage turns on what the cross-complaint alleges, not on how the case started. Tender it promptly; late notice is a common reason carriers deny a defense.

Talk to a California business litigation attorney

If your company has been served with a cross-complaint, or you are the defendant and need to bring claims of your own, call (909) 235-6116 or contact us online. Kolmogorov Law, P.C. is at 327 Magnet, Irvine, CA 92618, and represents businesses in Orange County, Los Angeles, and throughout California. See also our first 30 days guide, our pleadings and motions overview, and the civil litigation deadlines guide.

This page provides general information about California law and is not legal advice. Outcomes depend on the pleadings, the contract, the facts, and the court.