Burden of Proof in Tax Court: Who Has To Prove What

The IRS sent you a Notice of Deficiency with numbers you know are wrong. Here is the question that shapes everything that follows: do you have to prove the IRS wrong, or does the IRS have to prove itself right?

Usually, you have to prove the IRS wrong. That surprises people, because in an ordinary lawsuit the person making the claim is the one who has to prove it. In Tax Court the IRS's numbers walk into the courtroom presumed correct—and around 89% of petitioners carry the burden of knocking them down without a lawyer.

But "usually" is not "always." There are five specific situations where the law moves a burden onto the IRS, and a short list of issues—fraud chief among them—where the burden was never yours to begin with. Knowing them changes what you plead in your petition, what you demand in discovery, and how you build your evidence. This guide is the map.

One scope note before the map: this is the law of deficiency cases—the standard "the IRS says you owe more tax" case that follows a Notice of Deficiency. Other kinds of Tax Court cases run on different review standards. In a Collection Due Process appeal, the court usually reviews the IRS's collection decision only for abuse of discretion, and in an innocent spouse case the court takes a fresh look at the relief request under that statute's own rules. If that is your case, start with those guides.

The Baseline: The IRS Is Presumed Correct

The presumption comes from the Supreme Court. In Welch v. Helvering, 290 U.S. 111 (1933), Justice Cardozo put it in one sentence: "[The Commissioner's] ruling has the support of a presumption of correctness, and the petitioner has the burden of proving it to be wrong."

The Tax Court's own rule says the same thing. Tax Court Rule 142(a) provides:

The burden of proof shall be upon the petitioner, except as otherwise provided by statute or determined by the Court; and except that, in respect of any new matter, increases in deficiency, and affirmative defenses, pleaded in the answer, it shall be upon the respondent.

Two vocabulary notes, because the rule uses both words: in Tax Court captions you are the petitioner and the IRS is the respondent. And the answer is the IRS's formal, point-by-point response to your petition—IRS counsel files it within 60 days of the Court serving your petition, as covered in What Happens After You File Your Tax Court Petition.

Now read the rule again, because the exceptions are built right into it. The burden starts on you—but Rule 142(a) itself puts the burden on the IRS for new matter, increases in deficiency, and affirmative defenses raised in its answer, and it points to the statutes (chiefly IRC § 7491) that move the burden in other situations. The rest of this article walks through each one.

Three Terms in Plain English

The burden rules only make sense once you separate three ideas that sound alike:

• Burden of persuasion. Who has to convince the judge. If the evidence ends up dead even, the side carrying this burden loses. This is what people usually mean by "the burden of proof."
• Burden of production. Who has to come forward with evidence first on an issue. A production burden can be satisfied and then the fight moves on—it decides who goes first, not who wins.
• Standard of proof. How convincing the evidence must be. The default in Tax Court is a preponderance of the evidence—more likely than not. Fraud requires the much higher clear and convincing standard: evidence showing the fact is highly probable, well beyond a coin-flip's edge.

Keep these separate and the five shifts below stop being legal trivia and start being tools.

Shift 1: Credible Evidence—§ 7491(a)

Congress added IRC § 7491 in the IRS Restructuring and Reform Act of 1998. Under § 7491(a), if you introduce "credible evidence with respect to any factual issue relevant to ascertaining the liability" for income, estate, or gift tax, the burden of persuasion on that issue shifts to the IRS.

But the shift comes with prerequisites, and they do the real work. You must have:

1. Complied with the substantiation requirements in the Code for the item—so the strict-substantiation regimes (travel and vehicle records under § 274(d), charitable acknowledgment letters under § 170(f)) still bind you in full;
2. Kept the records the Code requires and cooperated with reasonable IRS requests for witnesses, information, documents, meetings, and interviews.

One misunderstanding worth correcting: the statute's net-worth limits apply only to partnerships, corporations, and trusts. Individuals face no net-worth ceiling under § 7491(a). And a coordination rule in § 7491(a)(3) says the shift does not apply where another provision of the tax code sets its own burden rule for the issue—which is why the penalty and information-return rules below operate on their own tracks.

The statute never defines "credible evidence." The Tax Court's working definition, set out in Higbee v. Commissioner, 116 T.C. 438 (2001), comes from the 1998 conference report: evidence of a quality that, after critical analysis, the court could base a decision on if no contrary evidence were offered. That is legislative history as the courts apply it, not statutory text—but it tells you what you are aiming for: real documents and specific testimony, not a bare "the IRS is wrong."

Now the honest part: this shift almost never decides a case. The Tax Court said so directly in Knudsen v. Commissioner, 131 T.C. 185 (2008): "In a case where the standard of proof is preponderance of the evidence and the preponderance of the evidence favors one party, we may decide the case on the weight of the evidence and not on an allocation of the burden of proof." Knudsen adopted the Eighth Circuit's reasoning in Blodgett v. Commissioner, 394 F.3d 1030, 1039 (8th Cir. 2005), which it quoted for the point that "a shift in the burden of preponderance has real significance only in the rare event of an evidentiary tie."

Translate that: if your evidence is stronger, you win with or without the shift. If your evidence is weaker, the shift never triggers, because you failed the substantiation-and-cooperation prerequisites. The shift only matters in a genuine tie—and ties are rare. The strategy that follows is simple: raise § 7491(a) in your petition (it costs nothing), then build your case as if the burden stays with you, because the same records and cooperation that trigger the shift are what win the case anyway.

Shift 2: Income Invented From Statistics—§ 7491(b)

Section 7491(b) is narrow but real. For an individual, the IRS bears the burden of proof on any item of income it reconstructed "solely through the use of statistical information on unrelated taxpayers."

This is aimed at the workups where the IRS, lacking any actual information about you, fills in an income figure from Bureau of Labor Statistics tables or similar averages—something that happens most often in substitute-for-return cases. The word "solely" limits it: if the IRS has any taxpayer-specific evidence in the mix, the shift is off. If your deficiency rests on invented statistical income, see Substitute for Return Disputes in Tax Court, where these reconstructions come up.

Shift 3: Penalties—The IRS Produces First Under § 7491(c)

For penalties, the roles genuinely reverse. Section 7491(c) says: "Notwithstanding any other provision of this title, the Secretary shall have the burden of production in any court proceeding with respect to the liability of any individual for any penalty, addition to tax, or additional amount imposed by this title."

The framework comes from Higbee v. Commissioner, 116 T.C. 438 (2001): the IRS must come forward first with evidence that the penalty is appropriate. Before it does, you have nothing to disprove. This covers penalties and additions to tax against individuals—including the failure-to-file and estimated-tax additions—though it is a burden of production, not persuasion, and it does not apply to corporations.

Part of what the IRS must produce is its own paperwork. In Chai v. Commissioner, 851 F.3d 190 (2d Cir. 2017), the Second Circuit held that compliance with the written supervisory-approval requirement of § 6751(b) is part of the IRS's § 7491(c) burden, and the Tax Court followed in Graev v. Commissioner, 149 T.C. No. 23 (2017). If the IRS cannot produce timely written approval, the penalty falls—no matter how correct it was on the merits. That lever has its own dedicated guide: The Penalty Defense That Costs You Nothing: § 6751(b).

The trap to avoid: "the IRS has the burden" does not mean you can sit silent. Higbee also holds that penalty defenses—reasonable cause and good faith under § 6664(c), substantial authority, and the rest—remain yours to prove. The split is: the IRS produces the penalty predicate; you prove the defense. Once the IRS satisfies its production burden, a petitioner who puts on no reasonable-cause evidence loses the penalty issue. The defenses themselves are covered in How To Fight the IRS Accuracy-Related Penalty in Tax Court.

Shift 4: A Wrong 1099 or W-2—§ 6201(d)

If your case is built on a third-party information return—a 1099-NEC, 1099-K, 1099-C, 1099-R, W-2, W-2G, or SSA-1099—IRC § 6201(d) is the shift to know. Added by the Taxpayer Bill of Rights 2 in 1996, it has two triggers:

1. You assert a reasonable dispute with the item of income reported on the form; and
2. You have fully cooperated with the IRS, including giving reasonable, timely access to the witnesses, information, and documents in your control.

If both are met, "the Secretary shall have the burden of producing reasonable and probative information concerning such deficiency in addition to such information return."

In plain terms: an information return is not self-proving. Once you trigger § 6201(d), the IRS cannot rest on the bare form—it must come forward with the payer's underlying records or other substantive evidence that the income was really yours in that amount.

Both triggers take real content. A flat "I dispute it" is not a reasonable dispute; you have to articulate why the form is wrong—wrong payee, wrong amount, gross figure instead of net, duplicate reporting, identity theft. And cooperation is a record you build over time: answering the CP2000 and exam letters, producing what is asked, and documenting your attempts to get the payer to correct the form.

A cautionary illustration of what happens when nobody invokes the shifts: in Delgado v. Commissioner, T.C. Summ. Op. 2023-8, the court noted that the petitioners had not raised § 6201(d) at all and had produced no evidence they met § 7491(a)'s preconditions—so the default Rule 142(a) burden simply governed. (That is a summary opinion, which under § 7463(b) may not be treated as precedent; it is an illustration, not authority.) The shifts do not apply themselves. You have to raise them.

The developed playbook—payer-correction letters, transcript pulls, discovery demands—lives in Unreported Income Disputes in Tax Court and, for platform forms, Form 1099-K Disputes in Tax Court.

Shift 5: The Naked Assessment—No Evidence, No Presumption

The presumption of correctness assumes the IRS actually determined something. When the deficiency asserts unreported income, several federal appeals courts require the IRS to first show a minimal evidentiary foundation—some predicate evidence linking you to the income-producing activity. Without it, the presumption never attaches at all.

The Supreme Court planted the roots. Helvering v. Taylor, 293 U.S. 507 (1935), held that a determination "shown to be without rational foundation and excessive" will not be enforced merely because the taxpayer failed to establish the correct amount. And in United States v. Janis, 428 U.S. 433 (1976), the Court described such a determination as a "'naked' assessment without any foundation whatsoever."

The circuit courts built the working rule. In Weimerskirch v. Commissioner, 596 F.2d 358 (9th Cir. 1979), the Ninth Circuit refused to give the presumption to an unreported-income determination unsupported by any foundation. In Portillo v. Commissioner, 932 F.2d 1128 (5th Cir. 1991), the Fifth Circuit held that a bare match of a disputed Form 1099 against the return, with no investigation, is not a determination entitled to the presumption.

One caveat, because this is circuit-developed law: the rule is well-established in the Fifth and Ninth Circuits and recognized in several others, but its precise strength varies. The Tax Court follows the precedent of the circuit your case can be appealed to (Golsen v. Commissioner, 54 T.C. 742 (1970))—for an individual, generally the circuit covering the state where you lived when you filed your petition—so where you live matters here.

And keep it honest: knocking out the presumption does not win the case by itself. The IRS loses its head start and must support the determination with actual evidence—but the fight continues on the merits. The full unreported-income playbook is in Unreported Income Disputes in Tax Court.

Burdens That Start on the IRS and Stay There

A few issues never carry a taxpayer burden at all.

Civil fraud. Under IRC § 7454(a), in any proceeding involving whether the petitioner has been guilty of fraud with intent to evade tax, "the burden of proof in respect of such issue shall be upon the Secretary." Rule 142(b) sets the standard: the burden "is on the respondent, and that burden of proof is to be carried by clear and convincing evidence." That is the full burden of persuasion, at a heightened standard, and it never shifts to you on the fraud issue. The 75% penalty and its defenses are covered in The 75% Fraud Penalty: Who Has To Prove It.

New matter and increased deficiencies. Straight from Rule 142(a): if the IRS's answer raises a ground that was not in the Notice of Deficiency, or asks for more tax than the notice determined, the IRS bears the burden of persuasion on that piece. The practical move: when the answer arrives, compare it line by line against the notice, and flag anything that needs different evidence than the notice did or pushes the number up.

Affirmative defenses. Same rule—affirmative defenses the IRS pleads in its answer under Rule 39 are the IRS's to prove.

Transferee liability. If the IRS claims you are liable as the transferee of someone else's assets, Rule 142(d) puts the burden of proving that liability on the IRS.

The trap hiding inside this rule. "The IRS has to prove it" does not mean you can ignore the answer. In a regular case, if the answer contains affirmative allegations, Tax Court Rule 37 gives you 45 days from service to file a Reply. Skip it and the allegations start out treated as denied—but the IRS can then move to have them deemed admitted, and a granted motion hands the IRS facts it otherwise had to prove at trial. And if you do reply, expressly admit or deny each allegation, because anything you leave unaddressed in a filed Reply is deemed admitted. The mechanics are in What Happens After You File Your Tax Court Petition.

The flip side: your own affirmative defenses. Rule 39 runs in both directions—each party must plead its own affirmative defenses, and that includes you. If you believe the IRS acted too late, the statute of limitations is an affirmative defense you must plead in your petition and then prove; leave it out and you risk forfeiting what might be your best issue. See Understanding IRS Statutes of Limitations.

The Whole Map in One Table

What This Means for Your Evidence Workload

Here is the practical translation, because the doctrine only matters if it changes what you do.

Build as if every disputed item is yours to prove, more likely than not. For each adjustment on the notice, that means a document trail: the receipt, bank statement, contract, or contemporaneous log that shows your number, plus testimony that is specific rather than vague. If some records are missing, do not abandon the item—for certain expense categories judges can accept a reasonable estimate, though never for the strict-substantiation items; How To Prove Your Business Expenses explains the limits. The how-to for assembling and organizing that proof is How To Prepare Your Evidence for Tax Court—and it is also why petitioners present their case first at trial.

If the audit went badly—or you ignored it—you are not locked out. The Tax Court decides your case fresh, on the record made in that court, not on the audit file. Records the examiner never saw can still come into evidence. Understand the cost, though: the cooperation prerequisites of § 7491(a) and § 6201(d) look back at how you behaved during the exam, so shifts you might have earned may be gone. You can still win the ordinary way—on the weight of the evidence—and cooperating with the IRS attorney and Appeals from this point forward still moves cases toward settlement.

Treat the shifts as backstops, not the plan. After Knudsen, a burden shift changes the outcome only in an evidentiary tie. The same substantiation and cooperation that trigger § 7491(a) and § 6201(d) are what win cases outright—so the work is identical either way. What the shifts add is leverage: a penalty the IRS cannot support, a 1099 it cannot back up, a foundation it cannot show.

Put the framework in writing. Your pretrial memorandum is where you lay out Rule 142(a), the shifts you have triggered, and what the IRS must produce. And use discovery to demand the IRS's § 6201(d) production and its § 6751(b) approval form if it has not volunteered them.

Stipulate with the burden in mind. Anything in the stipulation of facts no longer needs proving—by either side. That cuts both ways: stipulations shrink your evidence workload, but stipulating to a fact you actually dispute hands the IRS a win on an issue it might have had to prove.

How To Check What the IRS Is Asserting

Before you argue numbers, verify them. Two IRS transcripts show you the IRS's side of the case, and you can pull both yourself, free, through IRS.gov's Get Transcript tool (with mail and automated-phone alternatives if you cannot pass the online identity checks):

• The Wage & Income transcript lists every information return the IRS actually received under your SSN—every W-2, 1099, and W-2G. This is the raw material of a CP2000 or unreported-income case. Compare each form against the notice: a deficiency built on a form that is wrong, duplicated, or not on the transcript at all is exactly the material of a § 6201(d) "reasonable dispute."
• The Account Transcript shows what the IRS has actually assessed for the year, and when.

How to get both, and how to read them, is covered in How To Get and Read Your IRS Transcripts and How To Read IRS Transcript Codes.

The IRS's own burden-of-proof page frames the taxpayer's burden as the responsibility to prove entries, deductions, and statements—a recordkeeping duty that IRC § 6001 makes law. Notice what that means: the agency's working assumption is that the burden is yours. The five shifts exist, but nobody applies them for you.

What To Do Now

1. If you have a Notice of Deficiency, calendar the deadline first. You have 90 days from the date on the notice (150 days if the notice is addressed to you outside the United States) to file a Tax Court petition, and it cannot be extended.
2. Keep and organize your records. Substantiation is both the prerequisite for every shift and how cases are actually won. For issue-specific standards, see the how-to-prove series: EITC and dependents, charitable deductions, business expenses, and business-versus-hobby.
3. Cooperate on the record. Answer the CP2000 and exam letters, produce what is asked, attend the meetings—and document every request and every response. Non-cooperation forfeits both § 7491(a) and § 6201(d).
4. Pull your transcripts before you argue numbers. The Wage & Income transcript and Account Transcript show what the IRS received and what it assessed.
5. Plead the shifts in your petition. Assignments of error—the numbered paragraphs of your petition listing each mistake you say the IRS made—invoking § 7491(a) generally, § 7491(c) for any penalty, and § 6201(d) for any disputed information return cost nothing to include. Delgado shows what silence gets you. Then build the case as if the burden stayed with you.
6. Know that a small case changes nothing here. Electing small-case procedures under IRC § 7463 (available at or below $50,000 per year) relaxes formality but does not change any burden rule—and S-case decisions are not precedent. See Small Case or Regular Case: Which Should You Choose?
7. Remember where cases actually end. More than 99% of Tax Court cases resolve without a trial on the merits. A clean substantiation-and-cooperation record is precisely what moves IRS Appeals and Counsel toward concession.

Get Help

The burden framework is learnable, and the moves it suggests—keep records, cooperate, plead the shifts, pull transcripts—are all within a pro se petitioner's reach. But representation measurably helps: in the most recent National Taxpayer Advocate data, represented petitioners prevailed at trial in whole or in part about 23% of the time versus about 12% for pro se petitioners.

If your income is at or below 250% of the poverty line (about $39,900 for a one-person household, plus $14,200 for each additional member) and your dispute is at or below $50,000 per tax year, you may qualify for free representation through a Low Income Taxpayer Clinic. LITCs handle Tax Court cases regularly, and burden-of-proof arguments are their bread and butter.

Resources

Statutes and rules:

• IRC § 7491 — Burden of proof
• IRC § 6201 — Assessment authority; § 6201(d) information-return dispute rule
• IRC § 7454 — Burden of proof in fraud cases
• IRC § 7463 — Small tax case procedures
• IRC § 6001 — Recordkeeping duty
• IRC § 6664 — Reasonable cause exception
• Tax Court Rule 142 — Burden of Proof
• Tax Court Rule 39 — Pleading Special Matters (affirmative defenses)
• Tax Court Rule 37 — Reply (the 45-day response to affirmative allegations)

IRS guidance:

• IRS, "Burden of proof" — the IRS's recordkeeping-first framing of the taxpayer's substantiation duty

Cases cited:

• Welch v. Helvering, 290 U.S. 111 (1933) — the presumption of correctness
• Helvering v. Taylor, 293 U.S. 507 (1935) — a determination without rational foundation will not be enforced
• United States v. Janis, 428 U.S. 433 (1976) — the "naked assessment" language
• Golsen v. Commissioner, 54 T.C. 742 (1970) — the Tax Court follows the law of the circuit of appeal
• Weimerskirch v. Commissioner, 596 F.2d 358 (9th Cir. 1979) — no presumption without a foundation for unreported income
• Portillo v. Commissioner, 932 F.2d 1128 (5th Cir. 1991) — a bare 1099 match is not a determination entitled to the presumption
• Higbee v. Commissioner, 116 T.C. 438 (2001) — the § 7491(c) production framework; defenses remain the taxpayer's
• Blodgett v. Commissioner, 394 F.3d 1030 (8th Cir. 2005) (Eighth Circuit opinion PDF) — a burden shift has real significance only in an evidentiary tie
• Knudsen v. Commissioner, 131 T.C. 185 (2008) (U.S. Tax Court, DAWSON) — burden shifts matter only in an evidentiary tie; quotes and adopts Blodgett
• Chai v. Commissioner, 851 F.3d 190 (2d Cir. 2017) — § 6751(b) approval is part of the IRS's § 7491(c) burden
• Graev v. Commissioner, 149 T.C. No. 23 (2017) (U.S. Tax Court, DAWSON) — the Tax Court follows Chai
• Delgado v. Commissioner, T.C. Summ. Op. 2023-8 (U.S. Tax Court, DAWSON) — the default burden governs when no shift is raised; a summary opinion, not precedent under § 7463(b)

Companion articles on TaxCourtHelp:

• How To File Your Tax Court Petition — where the assignments of error invoking the shifts go
• What Happens After You File Your Tax Court Petition — the answer, the 45-day Reply, and the road to settlement
• Collection Due Process Hearings: Your Right To Challenge IRS Liens and Levies — collection cases run on a different review standard
• How To Request Innocent Spouse Relief — relief decided under that statute's own rules
• Understanding IRS Statutes of Limitations — the affirmative defense you must plead yourself
• How To Prepare Your Evidence for Tax Court — assembling the proof this article says you need
• Unreported Income Disputes in Tax Court — the § 6201(d) and predicate-evidence playbook in depth
• Form 1099-K Disputes in Tax Court — § 6201(d) applied to platform forms
• Substitute for Return Disputes in Tax Court — where § 7491(b) statistical reconstructions bite
• The Penalty Defense That Costs You Nothing: § 6751(b) — the production-burden lever on penalties
• How To Fight the IRS Accuracy-Related Penalty in Tax Court — the Higbee framework and reasonable cause
• The 75% Fraud Penalty: Who Has To Prove It — § 7454(a) and clear-and-convincing evidence
• What To Expect at Your Tax Court Trial — why you present first
• How To Write Your Tax Court Pretrial Memorandum — where the burden framework goes on paper
• How To Handle Discovery and Pretrial Preparation in Tax Court — demanding the IRS's production
• Stipulation of Facts: Tax Court Rule 91 — what no longer needs proving
• How To Respond to a CP2000 Notice — where the cooperation record starts
• How To Respond to an IRS Audit — the exam-stage cooperation § 7491(a) and § 6201(d) both require
• You Just Got a 90-Day Letter From the IRS. Here's What It Means. — the notice that starts the clock
• How To Get and Read Your IRS Transcripts and How To Read IRS Transcript Codes — verifying what the IRS is asserting
• Small Case or Regular Case: Which Should You Choose? — the election that changes formality, not burdens
• How To Find and Use a Low Income Taxpayer Clinic — free representation if you qualify

This article is for informational purposes only and does not constitute legal or tax advice. For advice specific to your situation, consult a qualified tax professional or attorney.