§ 428.40.Separate Document

Section 428.40 states a formatting rule in a single sentence: a cross-complaint must be a separate document. It cannot be folded into the answer or any other pleading as a section or attachment.

The rule keeps the case file organized as cross-claims proliferate. Because a cross-complaint can run in several directions at once — against the original plaintiff under § 428.10(a), against a new third party under § 428.10(b), or joined with other causes under § 428.30 — treating it as its own document makes it easier for the clerk, the court, and the parties to track which claims are pending against whom.

This separateness also matters for the mechanics that follow: § 428.60 requires service of the cross-complaint in a specific manner, and § 428.50 sets independent filing deadlines for it, both of which presuppose the cross-complaint exists as a document distinct from the answer it may accompany.