What Happens If You Lie Under Oath: Penalties and Consequences

If you lie under oath, you can be charged with perjury, a federal felony punishable by up to five years in prison and a fine of up to $250,000, and that is only the criminal exposure.¹² Inside the case where the lie happened, a judge can throw out your evidence, order you to pay the other side’s attorney fees, enter judgment against you, or dismiss your case outright. And because perjury is classified as a crime of dishonesty, the conviction follows you into employment, professional licensing, and every future courtroom you ever walk into.

What Actually Counts as Perjury

Not every false statement under oath is a crime. Federal prosecutors have to prove four things beyond a reasonable doubt: you were under a lawful oath or signing under penalty of perjury, the statement was false, you knew it was false when you said it, and the lie was “material,” meaning it had the potential to influence the outcome of the proceeding.¹

Materiality is the element people underestimate. Lying about your age at a deposition probably is not material unless age is somehow at issue in the case. Lying about how fast you were driving before a crash almost certainly is. An honest mistake does not count. Neither does a genuine lapse in memory. The government has to show you deliberately said something you knew to be untrue.

Where the Oath Applies

The witness stand at trial is only one of several places where testimony is sworn. The exposure is the same anywhere a formal oath or a penalty-of-perjury declaration attaches:

Depositions, where attorneys question witnesses under oath before trial and a court reporter preserves every word.³
Affidavits, declarations, tax returns, bankruptcy filings, and other signed documents submitted under penalty of perjury, which carry the same legal weight as live testimony.
Grand jury proceedings, where a separate federal statute specifically targets false declarations.
Administrative hearings before licensing boards, immigration courts, and workers’ compensation panels.
Congressional testimony, where witnesses are sworn in and false answers carry the same consequences.

One boundary worth knowing: lying on an immigration application or during a naturalization interview is handled on a separate track. A noncitizen who uses willful misrepresentation to obtain a visa, entry, or any other immigration benefit is permanently inadmissible, and a naturalized citizen who concealed a material fact can be stripped of citizenship through a civil denaturalization lawsuit.⁴⁵ Those consequences stack on top of any criminal charge, not instead of it.

The Criminal Penalties

Federal law reaches lying under oath through several overlapping statutes. Prosecutors pick among them based on where the lie happened and what they can most easily prove.

The general perjury statute, 18 U.S.C. § 1621, covers any false material statement made under oath or under penalty of perjury in any federal setting where the oath is authorized. The maximum sentence is five years, and the maximum fine for an individual convicted of a federal felony is $250,000.¹²

When the false statement happens in a federal court or before a grand jury, prosecutors often charge under 18 U.S.C. § 1623, which is easier to prove. The maximum penalty is the same five years and $250,000. Section 1623 also offers something the general statute does not: a recantation defense. If you admit the false statement during the same proceeding, before the lie has substantially affected the outcome and before it has become obvious the falsehood will be exposed, you cannot be prosecuted under this section.⁶ The window is narrow. You have to come clean quickly, on your own initiative, and before the damage is done.

Convincing someone else to lie is its own crime. Subornation of perjury under 18 U.S.C. § 1622 carries the same five-year maximum and $250,000 fine, which means a lawyer, party, or anyone else who coaches a witness to lie can face the same prison exposure as the witness.⁷

And there is a trap that catches people who never thought they were “testifying.” Under 18 U.S.C. § 1001, lying to a federal agency, on a form or in a conversation, is a felony punishable by up to five years, with no oath required.⁸ Federal agents often know the answer before they ask the question; the lie itself becomes the charge.

Every state also treats perjury as a felony. Maximum prison sentences generally run between two and seven years, and maximum fines typically fall between $5,000 and $25,000, with heavier penalties in some states when perjury occurs in a capital case or contributes to a wrongful conviction.

What Happens Inside the Case Where You Lied

Even when no criminal charge is filed, a judge who catches a witness lying has serious tools. The judge can order the false testimony stricken from the record and instruct the jury to ignore it. Federal rules let the court bar a party from using any evidence tied to a dishonest discovery response, which can collapse an entire theory of the case.⁹

Money sanctions are routine. Courts regularly order the dishonest party to pay the other side’s attorney fees and expenses caused by the misconduct.⁹ In serious cases, a judge can enter a default judgment against the lying party, hand the win to the other side, or dismiss the case entirely. A dishonest deponent can also be held in contempt.

Then there is the credibility problem, which is where most perjury does its real damage in civil cases. Once a jury catches a witness in one lie, the rest of that witness’s testimony becomes suspect. Jurors do not carefully sort the true parts from the false parts. They write the witness off.

What a Conviction Does to the Rest of Your Life

Because perjury is a felony and specifically a crime of dishonesty, a conviction triggers a longer list of collateral consequences than most felonies.

Future testimony. Under the rules of evidence in both federal and state courts, any party can introduce your prior conviction for a dishonesty crime to attack your credibility, regardless of how old it is. Every time you take the stand for the rest of your life, the other side can tell the jury you were convicted of lying under oath.
Professional licenses. Boards governing lawyers, doctors, accountants, nurses, and other regulated professions treat perjury as a crime of moral turpitude. Suspension, revocation, or denial is on the table. For attorneys, a perjury conviction almost always ends in disbarment.
Law enforcement careers. A finding of dishonesty can place an officer on a Giglio list, requiring prosecutors to disclose the credibility problem to every defense attorney in every case. Officers on that list often cannot effectively testify, which means they often cannot keep their jobs.
Firearms and voting. A federal felony conviction bars firearm possession under federal law. Many states restrict or strip voting rights after a felony, with restoration processes that vary.
Employment. A felony involving dishonesty is one of the hardest records to overcome on a background check. Jobs involving financial trust, security clearances, or fiduciary duty are largely closed off.

Why Prosecutions Are Rare but Consequences Still Arrive

Formal perjury prosecutions are uncommon. Proof is difficult, prosecutors have limited resources and tend to focus on the underlying case rather than a satellite perjury charge, and materiality gives defense attorneys a genuine legal argument to work with. If there is any room to say the false statement could not have affected the outcome, the charge may not survive.

That rarity is misleading. Judges deal with dishonest witnesses through the in-case remedies above, which move faster and require a lower burden of proof than a criminal conviction. A witness whose lie surfaces during a civil trial may never be indicted, but they can still lose the case, pay the other side’s lawyers, and carry the reputational damage for years. The criminal charge is the headline risk. The ordinary consequences are what most people who lie under oath actually face.

1
Office of the Law Revision Counsel. 18 USC 1621 – Perjury Generally
2
Office of the Law Revision Counsel. 18 USC 3571 – Sentence of Fine
3
Legal Information Institute. Federal Rules of Civil Procedure Rule 30 – Depositions by Oral Examination
4
Office of the Law Revision Counsel. 8 USC 1182 – Inadmissible Aliens
5
govinfo. 8 USC 1451 – Revocation of Naturalization
6
Office of the Law Revision Counsel. 18 USC 1623 – False Declarations Before Grand Jury or Court
7
Office of the Law Revision Counsel. 18 USC 1622 – Subornation of Perjury
8
Office of the Law Revision Counsel. 18 USC 1001 – Statements or Entries Generally
9
U.S. District Court for the Northern District of Illinois. Federal Rules of Civil Procedure Rule 37 – Failure to Make or Cooperate in Discovery: Sanctions