California Code of Civil Procedure Section 1166 sets the pleading requirements for an unlawful detainer complaint: the complaint must be verified, must plead specific facts showing the landlord’s right to possession, must describe the property with reasonable certainty, must state the rent due if the case is based on nonpayment, must describe exactly how the termination notice was served, and must have the notice (and in most cases the written lease) attached.1California Legislative Information. California Code CCP – 1166 Miss any of these and the court can order the complaint amended before the case moves forward.
Verification Under Section 1166(a)
The complaint must be verified. That means a signed declaration under penalty of perjury that the facts alleged are true. Section 1166(a) specifically calls for the typed or printed name of the person making the verification, which is a departure from civil filings where an attorney signature alone often suffices.1California Legislative Information. California Code CCP – 1166
The verification itself follows the rules in CCP Section 446. The person signing swears the facts are true based on personal knowledge, except for matters stated on information and belief, which must be identified as such.2California Legislative Information. California Code CCP – 446 A property manager or agent with actual knowledge of the tenancy can verify; a lawyer who has only heard about the facts from the client generally cannot.
The Four Factual Allegations the Complaint Must Contain
Beyond the signature block, Section 1166 tells the drafter what the body of the complaint must actually say. There are four required elements.
First, the complaint must set forth the facts that entitle the landlord to recover possession. This is the substantive story of the case: who the parties are, what the tenancy is, and what the tenant did (or failed to do) that ended the right to possession.
Second, the property must be described with reasonable certainty. In practice, that is the full street address plus any apartment, suite, or unit number. A vague description or a missing unit number is a common defect on rejected complaints.
Third, if the case is filed under CCP 1161(2) for nonpayment of rent, the complaint must state the exact amount of rent owed. A round figure or an estimate is not enough; the number must match what the three-day notice demanded.
Fourth, the complaint must specifically describe how the termination notice was served on the tenant. This is where landlords stumble most often. Saying “the three-day notice was served on the tenant” does not satisfy the statute. The complaint must identify the method: whether the notice was handed to the tenant personally, left with another adult at the residence and then mailed, or posted on the door and mailed. That description can be made by completing the service fields on Judicial Council form UD-100 or by attaching a separate proof of service for the notice.1California Legislative Information. California Code CCP – 1166
The method matters because it controls when the notice period starts and whether the notice was legally effective at all. A complaint that pleads the wrong service method, or an ineffective one, gives the tenant a clean defense.
Optional Allegations and the 1161a Caption Rule
Section 1166 also permits, without requiring, allegations of fraud, force, or threats accompanying the entry or detainer, and claims for damages tied to those acts.1California Legislative Information. California Code CCP – 1166 These are add-ons a landlord may include when the facts support them.
One caption rule applies only to a specific kind of case. If the action is brought under CCP 1161a, typically a post-foreclosure eviction of a former owner or holdover occupant, the caption of the complaint must state: “Action based on Code of Civil Procedure Section 1161a.” Omitting that language on a 1161a case is a straightforward defect.1California Legislative Information. California Code CCP – 1166
Documents That Must Be Attached
Section 1166(d) requires two categories of attachments in every residential unlawful detainer complaint.
The first is a copy of the termination notice or notices served on the tenant. Whether that is a three-day notice to pay rent or quit, a three-day notice to cure or quit, a 30-day notice, a 60-day notice, or a 90-day notice, the actual document served must be attached to the complaint. If more than one notice was served (say, both a three-day and a 30-day), attach all of them.
The second is a copy of the written lease or rental agreement, including any addenda or attachments that form the basis of the complaint.1California Legislative Information. California Code CCP – 1166
The lease attachment has three exceptions. You do not need to attach a written lease if:
- The rental agreement is oral.
- The written lease is not in the landlord’s possession or the possession of any agent.
- The action is based solely on nonpayment of rent under CCP 1161(2).
For a month-to-month tenancy with no written agreement, alleging in the body of the complaint that the arrangement is oral satisfies the statute.1California Legislative Information. California Code CCP – 1166
What Happens If an Attachment Is Missing
A missing attachment does not kill the case. Section 1166 requires the court to grant the landlord five days of leave to amend the complaint and include what was left off.1California Legislative Information. California Code CCP – 1166
The consequence is time. Unlawful detainer is a fast-track proceeding, and five days spent curing a filing defect is five days the tenant remains in the unit, often without paying. The cost of getting the attachments right at filing is trivial compared to the delay of fixing them later.
Pleading the Notice Service Correctly
Because the service-of-notice allegation is the requirement most often fumbled, it deserves a second look. The complaint has two acceptable ways to satisfy it. One is to fill in the service section on UD-100 completely, checking the boxes that describe how, when, and on whom the notice was served. The other is to attach a separate proof of service for the notice that contains the same information.1California Legislative Information. California Code CCP – 1166
Either way, the complaint has to answer three questions on its face: what method was used, when service happened, and whether the method was one authorized by statute for the notice at issue. If the drafter cannot answer those three from the four corners of the complaint, the pleading is incomplete.
What Section 1166 Does Not Cover
Section 1166 governs what goes into the complaint. Several things that landlords commonly bundle in their minds with “the 1166 requirements” are actually governed by other statutes, and treating them as part of 1166 leads to trouble.
Just cause. For most residential tenancies of 12 months or longer, Civil Code 1946.2 requires that a termination be for a just cause listed in that statute and that the cause be stated in the notice.3California Legislative Information. California Civil Code 1946.2 Section 1166 does not create that requirement, but the factual allegations in a 1166 complaint have to align with a recognized just cause for covered tenancies, or the case fails on the merits regardless of how cleanly the pleading is drafted.
Service of the summons and complaint. How the summons and complaint reach the tenant, how many attempts are required for substituted service, and when service is complete are matters for other CCP sections, not 1166.
Response deadlines and default. When the tenant must answer, and what the landlord must file to take a default (including the Servicemembers Civil Relief Act military-status affidavit required by 50 USC 3931 before a court will enter default),4Office of the Law Revision Counsel. 50 USC 3931 – Protection of Servicemembers Against Default Judgments are downstream steps. A complaint that satisfies 1166 can still stall at the default stage if these other requirements are missed.
Unknown occupants. The prejudgment claim of right to possession under CCP 415.46, served to bind occupants who are not named defendants,5California Legislative Information. California Code CCP – 415.46 is a service-side procedure, not a 1166 pleading item.
Section 1166 is a checklist for the four corners of the complaint. Treat it that way, get the verification, the four allegations, the caption (when 1161a applies), and the attachments right, and the pleading itself will clear the first hurdle in a proceeding that gives you very little room to fix mistakes later.