Perjury in civil litigation happens when someone knowingly makes a material false statement in a court filing, affidavit, or discovery response that was signed under oath or under penalty of perjury. Federal law treats that lie the same whether it appears on the witness stand or buried in a declaration attached to a motion. The consequences can include court-ordered payment of the other side’s legal fees, dismissal of the lying party’s case, and federal criminal charges carrying up to five years in prison.
Most people picture perjury as something that happens at trial. In civil cases, the greater risk sits in the paperwork, because sworn filings drive a judge’s decisions long before anyone testifies.
What Counts as Perjury in a Civil Case
Three elements have to line up: the statement was made under oath or under penalty of perjury, it was material to the proceeding, and the signer knew it was false.
Under Oath or Under Penalty of Perjury
Perjury exposure attaches only when the signer was under oath or signed a declaration under penalty of perjury. 18 U.S.C. § 1621 covers both testimony given under oath before a tribunal and written statements signed under penalty of perjury as allowed by 28 U.S.C. § 1746.1Office of the Law Revision Counsel. 18 USC 1621 – Perjury Generally A letter to a judge that doesn’t include sworn language doesn’t carry the same risk.
You don’t need a notary. Under 28 U.S.C. § 1746, an unsworn written declaration has the same legal force as a notarized affidavit if the signer includes the statement “I declare under penalty of perjury that the foregoing is true and correct,” followed by a date and signature.2Office of the Law Revision Counsel. 28 USC 1746 – Unsworn Declarations Under Penalty of Perjury Most civil declarations use that format, and the perjury exposure is identical.
Material to the Case
Not every false statement qualifies. The lie must be material, meaning capable of influencing the decision the court is being asked to make. A typo in a street address almost certainly isn’t material. A false statement about whether a contract was signed, who was present at a meeting, or the extent of someone’s injuries almost certainly is.
Materiality is decided by the judge, not the jury, and the false statement doesn’t have to actually change the outcome. It only has to be the kind of statement capable of doing so. That’s where people underestimate the risk. A lie buried in a long discovery response can be material if it touches any disputed issue.
Known to Be False
The signer had to know the statement was false when they signed. Honest mistakes, faulty memory, and genuine confusion don’t qualify. Both § 1621 and 18 U.S.C. § 1623 require that the false declaration be made knowingly or willfully.3Office of the Law Revision Counsel. 18 USC 1623 – False Declarations Before Grand Jury or Court Intent is usually proved through circumstantial evidence: earlier drafts, contradictory emails, or testimony showing the person had access to accurate information and chose to disregard it.
Where the Risk Lives: Filings That Carry Perjury Exposure
Several categories of documents in a civil lawsuit require sworn statements. None of them are formalities.
Verified Complaints and Answers
A verified complaint requires the plaintiff to swear that the factual allegations are true, rather than relying on the attorney’s signature alone. Defendants file verified answers under the same obligation. These documents set the factual boundaries of the case, and courts treat their contents as sworn testimony.
Interrogatory Responses
During discovery, parties exchange written questions called interrogatories. Federal Rule of Civil Procedure 33 requires each response to be answered “separately and fully in writing under oath,” and the party answering, not just the attorney, must sign.4Legal Information Institute. Federal Rules of Civil Procedure Rule 33 – Interrogatories to Parties A misleading discovery response can do more damage than a lie at trial, because the other side may rely on it for months before the deception surfaces.
Summary Judgment Affidavits
When a party asks a judge to decide the case without a trial, the supporting affidavits effectively replace live testimony. Federal Rule of Civil Procedure 56 requires those affidavits to be based on personal knowledge, contain facts admissible as evidence, and show the signer’s competence to testify on the subject.5Legal Information Institute. Federal Rules of Civil Procedure Rule 56 – Summary Judgment A judge who rules on a false affidavit has been cheated out of the ability to reach a fair result.
Witness Declarations
Perjury liability isn’t limited to the parties. A non-party witness who signs a sworn affidavit or an unsworn declaration under penalty of perjury faces the same exposure. A friend who signs a false declaration to help someone in a divorce or contract dispute is at genuine legal risk.
What the Civil Judge Can Do
Before anyone gets near criminal court, the judge handling the lawsuit has substantial power to punish perjury. Those consequences often arrive faster and hit harder than a criminal case ever would.
Rule 11 Sanctions
Federal Rule of Civil Procedure 11 requires anyone signing a pleading, motion, or other paper to certify that the factual contentions have evidentiary support. When a court finds a violation, it can impose sanctions on the attorney, the party, or both.6Legal Information Institute. Federal Rules of Civil Procedure Rule 11 – Signing Pleadings, Motions, and Other Papers; Representations to the Court; Sanctions Sanctions commonly include orders to pay the opposing side’s reasonable attorney’s fees and litigation costs caused by the violation. Those bills add up. A discovery dispute set off by a false filing can generate tens of thousands of dollars in extra legal work, all of which the sanctioned party may have to cover. Non-monetary sanctions are also allowed, including remedial education orders or restrictions on future filings.
Terminating Sanctions
In the worst cases, a judge can end the case entirely. Terminating sanctions mean dismissing the lying party’s claims with prejudice or entering default judgment against them. Courts reserve this for conduct showing willfulness, bad faith, and fault. Judges don’t reach for it lightly, but when they do, the dishonest party loses without the case ever being decided on the merits.
Inherent Authority
Beyond the formal rules, federal courts have inherent authority to sanction bad-faith conduct. The Supreme Court confirmed in Chambers v. NASCO, Inc. that courts can use this power to impose monetary sanctions, including attorney’s fee awards, for litigation misconduct, even where the conduct is partly covered by existing rules.7Legal Information Institute. Inherent Powers of Federal Courts – Contempt and Sanctions Sanctions issued under inherent authority must be compensatory rather than punitive, with a direct link between the misconduct and the fees the other side incurred. This matters because it lets a judge address a pattern of dishonesty running through an entire case, not just a single filing.
Criminal Penalties
A civil judge can also refer the matter to federal prosecutors. Two statutes typically apply.
Under 18 U.S.C. § 1621, the general perjury statute, a conviction carries up to five years in prison plus a fine set under 18 U.S.C. § 3571, which caps individual felony fines at $250,000.8Office of the Law Revision Counsel. 18 USC 3571 – Sentence of Fine
Section 1623 specifically covers false declarations in federal court proceedings. The maximum penalties are the same, but § 1623 gives prosecutors a procedural edge: it allows an indictment based on two irreconcilably contradictory sworn statements without requiring the government to prove which one was the lie.3Office of the Law Revision Counsel. 18 USC 1623 – False Declarations Before Grand Jury or Court If you swore to one version of events in an affidavit and the opposite version in a deposition, the contradiction alone can support charges.
The general federal statute of limitations for perjury is five years from the date the offense was committed.9Office of the Law Revision Counsel. 18 USC 3282 – Offenses Not Capital That clock starts when the false statement is made, not when someone discovers it.
If the Other Side Lied in a Filing
Discovering a lie in an opposing filing is maddening, but the process for doing something about it follows a defined path.
Motion for Sanctions
The usual starting point is a Rule 11 motion. The motion must be filed separately from other motions and must describe exactly what conduct violated the rule.6Legal Information Institute. Federal Rules of Civil Procedure Rule 11 – Signing Pleadings, Motions, and Other Papers; Representations to the Court; Sanctions The judge decides whether to hold an evidentiary hearing. If one is held, the signer may be cross-examined about the challenged statements.
Burden of Proof
What you have to prove depends on what you’re asking for. Rule 11 sanctions require showing that the certification was objectively unreasonable. For a more severe remedy, like undoing a judgment that has already been entered, the bar is higher. A motion under Federal Rule of Civil Procedure 60(b)(3), which allows relief from a final judgment obtained through fraud or misrepresentation, requires clear and convincing evidence that the misconduct prevented a full and fair presentation of the case.10Legal Information Institute. Federal Rules of Civil Procedure Rule 60 – Relief From a Judgment or Order That motion also has to be filed within one year of the judgment.
You Generally Can’t Sue Someone for Perjury
One point surprises most people. In most jurisdictions, you cannot bring a separate lawsuit for damages against someone because they committed perjury against you. American courts have long declined to recognize a standalone civil tort for perjury, citing witness immunity and the need for finality in judgments. A few states have carved narrow exceptions, but in most places your remedies are limited to sanctions inside the existing case, a criminal referral, or a Rule 60(b) motion if the lie produced an unfavorable judgment.
If You Submitted Something False
The law offers two narrow windows to fix a false submission before the consequences become permanent.
The Rule 11 Safe Harbor
Before filing a Rule 11 sanctions motion with the court, the moving party must first serve it on the other side and wait at least 21 days. During that period, the party who submitted the challenged filing can withdraw or correct it, and if they do, the sanctions motion cannot be filed.6Legal Information Institute. Federal Rules of Civil Procedure Rule 11 – Signing Pleadings, Motions, and Other Papers; Representations to the Court; Sanctions This isn’t a free pass. If the falsehood has already caused damage, or the court raises the issue on its own, the safe harbor doesn’t apply. But for someone who catches a problem early, it offers a real chance to fix it.
Recantation Under Section 1623
For criminal purposes, § 1623 provides a recantation defense. If a person admits in the same continuous court proceeding that an earlier declaration was false, that admission bars prosecution, but only if two conditions are met: the false declaration has not yet substantially affected the proceeding, and it has not become apparent that the falsehood has been or will be exposed.3Office of the Law Revision Counsel. 18 USC 1623 – False Declarations Before Grand Jury or Court Coming clean works only if you do it before the damage lands and before you get caught. Once the other side has uncovered the lie, the defense disappears.
What Your Lawyer Has to Do
Attorneys have independent ethical duties that can override client confidentiality when perjury is involved. Under the American Bar Association’s Model Rule 3.3, adopted in some form by every state, a lawyer who knows that false material evidence has been offered to a court must take reasonable remedial measures, up to and including disclosure to the judge. That duty overrides the attorney’s normal obligation to protect client information.
In practice, the lawyer first counsels the client to correct the false statement. If the client refuses, the lawyer seeks to withdraw. If the court denies withdrawal, the lawyer is ultimately required to inform the court about the false evidence. Disclosure is treated as a last resort, but it is a real obligation. If your attorney finds that something you submitted is false, expect them to push hard for a correction. They’re following rules written for exactly this situation, and their license is on the line.