Yes, you can fill out U.S. Tax Court Form 4 yourself in about ten minutes if you have your taxpayer identification number ready and follow the U.S. Tax Court Rules of Practice and Procedure. Form 4 is the Statement of Taxpayer Identification Number, and it is the short, one-page document that tells the Tax Court who you are without putting your Social Security number into the public record.
The problem this form solves is a privacy one, and the immediate consequence of skipping it is severe. Under Tax Court Rule 20(b), the Court will not move your case forward until Form 4 is filed, and the judge can dismiss your petition for failure to prosecute if you ignore the requirement. According to U.S. Tax Court statistics, more than 25,000 petitions are filed each year, and a measurable share are delayed by missing or incorrect Form 4 filings.
In this guide, you will learn:
- 📝 How to complete every line of Tax Court Form 4 without errors
- ⚖️ Why Rule 20(b) requires a separate TIN statement and what happens if you skip it
- 👥 How married couples, businesses, estates, and trusts fill out the form differently
- 💻 How to file Form 4 through the DAWSON electronic filing system or by mail
- 🚫 The seven costliest mistakes that trigger dismissal, sealing problems, or identity exposure
What Tax Court Form 4 Is and Why It Exists
Tax Court Form 4 is a one-page filing called the Statement of Taxpayer Identification Number. The Court created it to comply with the privacy mandate inside Tax Court Rule 27, which forbids putting full Social Security numbers, employer identification numbers, or individual taxpayer identification numbers on any document that becomes part of the public docket. The Petition (Form 2) you file to start your case is public, but Form 4 is not.
Form 4 is held separately by the Clerk of the Court and is sealed from public view. That separation lets the IRS still match your case to the correct tax account while shielding your number from anyone reading the docket online. The plain-English idea is simple: the Court needs your TIN to manage your case, but the world does not need to see it.
The consequence of treating Form 4 as optional is real and painful. If you do not file it within the time set by the Court’s Standing Pretrial Order, the judge can issue an Order to Show Cause, and continued silence leads to dismissal under Rule 123. A dismissal in Tax Court usually means the deficiency the IRS proposed becomes final, and you owe the full assessed tax, penalties, and interest.
A real-world mini-scenario shows the stakes. Maria Lopez, a freelance graphic designer in Austin, filed her petition on time but forgot Form 4. The Court issued an Order to Show Cause sixty days later, and Maria almost lost her right to challenge a $14,200 deficiency before she mailed the form in.
A common misconception is that putting your SSN on the petition itself is enough. It is not, and doing so actually creates a second problem because the Court’s e-access policy treats unredacted TINs on public filings as a privacy violation that can require resealing.
Who Must File Form 4
Every petitioner who starts a case in the United States Tax Court must file Form 4. That includes individuals, married couples filing jointly, sole proprietors, partnerships, S corporations, C corporations, estates, trusts, and tax-exempt organizations. The rule lives inside Rule 20(b) and applies whether your case is a regular case or a small tax case (S case) under Rule 170.
The “why” is uniform across filer types. The Court must connect your petition to a specific tax account at the IRS, and the only reliable connector is the TIN that appears on the Notice of Deficiency or other determination letter. Without Form 4, the docket clerk cannot pair your file with the IRS administrative record.
Individual Petitioners
An individual taxpayer files one Form 4 listing one Social Security number. If the petitioner uses an Individual Taxpayer Identification Number (ITIN) instead of an SSN, that number goes on the form. The consequence of writing the wrong number is that the Court cannot match the case, and the IRS may file a motion to dismiss for lack of jurisdiction.
A common misconception is that a recently issued SSN replaces a prior ITIN automatically. It does not, and you should write the TIN that appears on the IRS notice you are challenging, not the newest one in your wallet.
Married Petitioners Filing Jointly
When spouses file a joint petition, they file one Form 4 that lists both Social Security numbers, with each spouse signing. The form has space for both numbers because the IRS account for a joint return is keyed to both TINs. If only one spouse signs the petition, only that spouse’s TIN goes on Form 4, and the other spouse is not a party.
A real example helps. David and Priya Chen filed a joint petition over a $9,800 deficiency tied to a 2024 joint return; they listed both SSNs on a single Form 4 and both signed, which preserved each spouse’s right to contest the liability.
Business, Estate, and Trust Petitioners
Entities use the Employer Identification Number (EIN) issued by the IRS. A C corporation lists its EIN, an S corporation lists its EIN, a partnership lists its EIN, and a trust or estate lists the EIN assigned on Form SS-4. If a sole proprietor is petitioning a deficiency tied to a Schedule C, the SSN goes on the form, not the business EIN, because the IRS account is the individual’s.
The consequence of choosing the wrong number for a flow-through entity is delay. Riverside Bakery LLC, a single-member LLC owned by Jordan Pierce, learned this when its accountant put the EIN on Form 4 for an income tax deficiency that actually belonged to Jordan’s individual return; the Court issued a deficiency-of-petition notice and required a corrected Form 4 within thirty days.
Where to Get Form 4
The official Form 4 lives on the Tax Court website. You can download the fillable PDF of Form 4 directly, and it is also available inside the DAWSON case management system once you start a petition. The Court does not charge for the form itself, although the Tax Court filing fee is $60 for the petition.
The form is plain and short, with five fillable areas: caption, docket number, petitioner name, taxpayer identification number, and signature. Do not use a third-party copy from a blog or template site, because those copies sometimes have outdated revision dates and may be rejected by the Clerk.
A common misconception is that you must wait for the Court to mail you a blank form. You do not, and waiting can eat into the 90-day petition window under IRC §6213(a) that controls deficiency cases.
Line-by-Line Walkthrough of Form 4
This section covers every line on the current revision of Form 4. The form is short, but each line carries a consequence if filled in wrong. Read each step and match it to the Notice of Deficiency or other IRS notice you are challenging.
Line 1: The Caption
The caption is the heading at the top that names the parties. It reads “Petitioner(s)” on one side and “Commissioner of Internal Revenue, Respondent” on the other. Write your full legal name exactly as it appears on the IRS notice and on your petition. The consequence of a name mismatch is that the Court cannot link Form 4 to the petition, and the Clerk may treat the form as non-conforming under Rule 23.
A common misconception is that nicknames or middle-initial variations do not matter. They do, and Robert “Bob” Allen should write “Robert J. Allen” if that is the name on the IRS notice, not “Bob Allen.”
Line 2: The Docket Number
The docket number is assigned by the Clerk after your petition is received. If you are filing Form 4 with the petition at the same time, leave this line blank and the Clerk will fill it in. If you are filing Form 4 after the petition, you must write the assigned docket number, which appears as a series of digits followed by a suffix (for example, 12345-26 or 12345-26S for a small case).
The consequence of leaving the docket number blank when you already have one is that Form 4 may be docketed as a new, unrelated filing. Aisha Brown learned this when her late-filed Form 4 was treated as a stray paper, and she had to call the Clerk’s office to have it merged with her real case.
Line 3: Petitioner Name
This is the place where you write the petitioner’s full legal name in print. For joint filers, write both names on the same line or stacked, matching the petition. For an entity, write the entity’s full legal name as registered with the secretary of state and as it appears on the IRS notice.
A common misconception is that you can use a “doing business as” name for a sole proprietorship. You cannot, and the IRS account is in the individual’s legal name.
Line 4: Taxpayer Identification Number
This is the most important line. Write the nine-digit SSN, ITIN, or EIN that matches the tax year and notice at issue. SSNs are formatted 123-45-6789, ITINs begin with a 9 and are formatted the same way, and EINs are formatted 12-3456789.
The consequence of writing the wrong TIN is dismissal risk and identity confusion. The Court cannot pull the right administrative file, the IRS cannot answer correctly, and your case stalls.
A common misconception is that you should write the TIN of whoever is paying the filing fee. You should not, and the TIN belongs to the taxpayer named on the IRS notice.
Line 5: Signature, Date, and Capacity
The petitioner signs and dates the form. If a representative signs, that representative must be admitted to practice before the Tax Court under Rule 200 and must list a Tax Court bar number. A non-attorney CPA or enrolled agent who is not admitted cannot sign Form 4.
The consequence of an unauthorized signature is that the form is treated as unsigned, and the Court can strike it. Greg Patel, an enrolled agent, signed Form 4 for a client without holding a Tax Court bar number; the Clerk rejected the form, and the client had to refile within the deadline.
Three Common Form 4 Scenarios
These three scenarios cover the situations the Clerk’s office sees most often. Each table shows the action you take and the docket consequence that follows.
Scenario 1: Solo W-2 Worker Filing Pro Se
| Filing Step | Docket Outcome |
|---|---|
| Single petitioner writes SSN on Form 4, signs, and files with petition | Clerk dockets case the same day and assigns docket number |
| Petitioner forgets Form 4 and files only the petition | Clerk issues Order to file Form 4 within 30 days |
| Petitioner ignores the Order | Judge dismisses under Rule 123, deficiency becomes final |
Scenario 2: Married Couple With Joint Deficiency
| Filing Step | Docket Outcome |
|---|---|
| Both spouses sign petition and one Form 4 listing both SSNs | Joint case proceeds, each spouse is a party |
| Only one spouse signs Form 4 with one SSN | Non-signing spouse is dropped, may lose innocent spouse relief timing |
| Spouses file two separate Form 4s in same case | Clerk consolidates if names and docket match |
Scenario 3: Small Business Entity Petitioning a Deficiency
| Filing Step | Docket Outcome |
|---|---|
| C corporation lists EIN, officer signs with title | Case proceeds as entity case |
| Corporation lists owner’s SSN by mistake | Clerk issues deficiency-of-petition notice, 30-day correction window |
| Corporation petition signed by non-admitted CPA | Petition stricken, Rule 60 requires admitted counsel for entities |
Filing Form 4: Paper vs. DAWSON Electronic Filing
You can file Form 4 by mail or through the Court’s DAWSON e-filing portal. DAWSON stands for Docket Access Within a Secure Online Network, and it is now the default for most petitioners who can use it. Both methods are valid, but they have different timing and privacy mechanics.
Paper filing requires you to mail Form 4 to the United States Tax Court at 400 Second Street NW, Washington, DC 20217, and the mailbox rule under IRC §7502 treats a timely postmark as a timely filing. Electronic filing is instantaneous and date-stamped at the moment of upload. The privacy consequence differs because DAWSON keeps Form 4 sealed automatically, while a paper filing relies on the Clerk to physically separate the form from the public record.
A common misconception is that DAWSON e-filing is only for lawyers. It is not, and any pro se petitioner can register a DAWSON account for free.
Comparison of Filing Methods
| Feature | Paper Filing | DAWSON E-Filing |
|---|---|---|
| Cost | $60 fee by check or money order | $60 fee paid by Pay.gov |
| Timing | Postmark date controls under IRC §7502 | Upload time stamps the filing |
| Privacy | Clerk manually seals Form 4 | System auto-seals from public docket |
| Confirmation | Mailed receipt or return-receipt card | Instant electronic receipt |
| Corrections | Mail a new Form 4 with cover letter | Upload corrected PDF in DAWSON |
How to E-File Through DAWSON
Open a DAWSON account using your email and a password that meets the system rules. Upload your petition first, then upload Form 4 as a separate PDF in the “Statement of Taxpayer Identification Number” slot. The system will mark Form 4 as sealed and not visible to the public.
The consequence of uploading Form 4 in the wrong slot is that it may briefly appear on the public docket. If that happens, file a motion to seal under Rule 27 right away. Linh Tran uploaded her Form 4 as an exhibit to her petition by mistake; she filed a same-day motion to seal, and the Clerk redacted the public version within 24 hours.
Common Mistakes to Avoid
These are the seven errors the Clerk’s office and Tax Court judges flag most often. Each one has a direct negative outcome.
- Writing the wrong TIN, which prevents the Court from matching your case to the IRS administrative file and risks dismissal for lack of jurisdiction.
- Putting your SSN on the petition itself, which exposes your number on the public docket and forces a motion to seal under Rule 27.
- Forgetting to sign Form 4, which makes the filing void and triggers an Order to file a corrected form within thirty days.
- Using a “doing business as” name instead of a legal name, which breaks the link between the form and the IRS notice.
- Letting a non-admitted CPA or enrolled agent sign for you, which violates Rule 200 and causes the form to be stricken.
- Filing only one Form 4 in a joint case when each spouse should be named, which can drop the non-signing spouse from the case and harm innocent spouse relief deadlines.
- Missing the deadline set in the Standing Pretrial Order, which is the most common path to dismissal under Rule 123.
- Mailing Form 4 without proof of mailing, which makes it hard to invoke the §7502 timely-mailing rule if the form is lost.
Do’s and Don’ts of Filing Form 4
These rules keep your case moving and your TIN private. Each item explains the reasoning so you can apply the principle to edge cases.
- Do use the exact name on the IRS notice, because the Clerk matches Form 4 to the petition by name and TIN together.
- Do file Form 4 at the same time as your petition, because doing so avoids the thirty-day deficiency-of-petition cycle.
- Do keep a stamped copy or DAWSON receipt, because proof of filing protects you if the Clerk’s office misplaces the original.
- Do redact your SSN from every other document you file, because Rule 27 requires redaction on all public filings.
- Do update Form 4 if your TIN changes mid-case, because an outdated number breaks IRS account matching during settlement.
- Don’t email a Form 4 to the Tax Court, because the Court does not accept email filings and the form will be ignored.
- Don’t combine Form 4 with the petition into one PDF, because DAWSON requires separate uploads to seal the TIN page.
- Don’t sign Form 4 with a power-of-attorney signature unless the agent is admitted to the Tax Court bar.
- Don’t use a previous year’s TIN if it has changed, because IRS records key on the current number.
- Don’t ignore an Order to file Form 4, because dismissal under Rule 123 makes the deficiency final and unappealable.
Pros and Cons of Filing Pro Se vs. With Counsel
Many Form 4 problems trace back to the choice between filing alone and hiring an admitted Tax Court practitioner.
- Pro: Filing pro se saves legal fees, which matters in small tax cases where the deficiency is $50,000 or less per year.
- Pro: Pro se petitioners control the pace of their case, which can speed up settlement with IRS Appeals.
- Pro: DAWSON makes pro se filing genuinely easy, which lowers the technical barrier for first-time filers.
- Pro: The Tax Court provides free pro se materials, which include sample petitions and a Form 4 template.
- Pro: Pro se filers can switch to counsel later by filing an Entry of Appearance (Form 7).
- Con: Pro se filers misfile Form 4 more often, which leads to the Order to Show Cause cycle.
- Con: Entities cannot file pro se in regular cases, because Rule 60 requires admitted counsel for corporations and most other entities.
- Con: Pro se filers may miss procedural defenses, such as statute-of-limitations arguments under IRC §6501.
- Con: Negotiating with IRS Counsel without a representative can produce weaker settlements.
- Con: A pro se mistake on Form 4 has the same dismissal consequence as a represented mistake.
Federal Rules That Govern Form 4
Form 4 sits at the intersection of two federal rule sets. The first is the Internal Revenue Code, which authorizes the Tax Court and sets the 90-day deadline to petition a Notice of Deficiency under IRC §6213(a). The second is the Tax Court Rules of Practice and Procedure, which contain the specific Form 4 requirements.
The plain-English version is that Congress sets the deadline to file the petition, and the Tax Court sets the rules for how to file. The consequence of confusing the two is missing the 90-day window because you spent the time perfecting Form 4 instead of mailing the petition.
A real-world example shows the order of operations. Marcus Hill received a Notice of Deficiency on March 1 and waited until late May to gather his Form 4 documents; he mailed everything on day 89 with certified mail return receipt and preserved his timely filing under §7502.
Rule 20(b): The TIN Statement Requirement
Rule 20(b) is the rule that creates Form 4. The plain-English explanation is that every petitioner must give the Court its TIN on a separate, sealed statement. The consequence of ignoring it is the Order to Show Cause and possible dismissal.
A common misconception is that Rule 20(b) applies only to deficiency cases. It does not, and the rule covers collection due process cases, innocent spouse cases, whistleblower cases, and partnership-level cases.
Rule 27: Privacy and Redaction
Rule 27 is the privacy rule that explains why Form 4 is sealed. It forbids putting full SSNs, taxpayer ID numbers, dates of birth, financial account numbers, and minors’ names on any public filing. The consequence of an unredacted public filing is that the Court can seal the document on its own motion and require a corrected version.
A real example: Sandra Webb filed a brief that included her bank account number for a refund argument; the Court sealed the brief sua sponte and ordered a redacted version within ten days.
Rule 123: Dismissal for Failure to Prosecute
Rule 123 is the dismissal rule that ends cases when a petitioner ignores Court orders. The plain-English version is “show up or lose.” The consequence of a Rule 123 dismissal in a deficiency case is that the IRS proposed deficiency becomes a final assessment, and the IRS can begin collection.
Court Rulings Worth Knowing
Two lines of Tax Court rulings matter for Form 4. The first concerns dismissal for procedural defects, where the Court has held that missing TIN statements support dismissal when combined with other defaults. The second concerns redaction, where the Court has ordered sealing whenever an unredacted TIN appears on the public docket.
In Wheeler v. Commissioner, 127 T.C. 200 (2006), the Court reinforced that procedural compliance with the Tax Court Rules is a prerequisite to merits review. The plain-English takeaway is that the Court will not bend the Form 4 rule even for sympathetic taxpayers.
A common misconception is that the Court will excuse Form 4 errors if the IRS already knows your TIN. It will not, because the Rule 20(b) duty runs to the Court, not to the IRS.
State Nuances and Cross-References
Form 4 is purely a federal form because the United States Tax Court is a federal Article I court. State tax tribunals such as the New York Division of Tax Appeals and the California Office of Tax Appeals have their own forms and TIN rules, and they do not accept federal Form 4. The plain-English point is that you cannot mix federal and state filings.
The consequence of confusing them is missed deadlines on both sides. Henry Ortiz mailed his California protest paperwork to the U.S. Tax Court by accident; the federal Clerk returned the package, and Henry had to scramble to meet his California deadline.
A common misconception is that a federal Tax Court ruling binds state tax agencies. It does not, although a federal determination on a federal issue often informs state adjustments under conformity statutes.
A Filled-In Form 4 Example
A clean example helps you see what a finished form looks like. Imagine Elena Rivera, an individual taxpayer challenging a $12,500 deficiency for tax year 2024.
- Caption: “Elena Rivera, Petitioner v. Commissioner of Internal Revenue, Respondent”
- Docket Number: blank if filed with petition; otherwise the assigned number such as 23456-26S
- Petitioner Name: “Elena Maria Rivera”
- Taxpayer Identification Number: 123-45-6789 (the SSN from her IRS Notice CP3219N)
- Signature: Elena’s handwritten signature, dated the same day as the petition
The consequence of getting all five fields right is that the Clerk dockets the case the same day, the IRS files an Answer within 60 days under Rule 36, and Elena moves toward IRS Appeals settlement or trial.
A common misconception is that Form 4 must be notarized. It does not, and adding a notary block does not improve the filing.
Frequently Asked Questions
Do I have to file Form 4 with my petition?
Yes. You should file Form 4 at the same time as the petition, because doing so avoids an Order to file the form within thirty days under Rule 20(b).
Can I email Form 4 to the Tax Court?
No. The Tax Court does not accept email filings; you must use DAWSON e-filing or mail the paper form to the Clerk in Washington, DC.
Is Form 4 visible to the public?
No. The Clerk seals Form 4 from the public docket under Rule 27, which protects your TIN from anyone reading the case file.
Do married couples file one Form 4 or two?
Yes, married couples filing a joint petition file one Form 4 listing both Social Security numbers, and both spouses sign it.
Can my CPA or enrolled agent sign Form 4 for me?
No. Only petitioners themselves or representatives admitted to the Tax Court bar under Rule 200 may sign Form 4 on a petitioner’s behalf.
Will the Court dismiss my case if I forget Form 4?
Yes, the Court can dismiss under Rule 123 if you ignore an Order to file Form 4, and the IRS deficiency then becomes final.
Does Form 4 cost extra to file?
No. Form 4 has no separate fee; only the petition carries the $60 filing fee, which you can pay through Pay.gov or by check.
Can I correct a wrong TIN on Form 4 after filing?
Yes. You file a corrected Form 4 in DAWSON or by mail with a short cover letter, and the Clerk substitutes it in the sealed file.
Is Form 4 required in small tax cases?
Yes. Small tax cases under Rule 170 follow the same Form 4 requirement as regular cases, with no exception for the simplified S-case track.
Does filing Form 4 extend the 90-day petition deadline?
No. The 90-day deadline under IRC §6213(a) is set by statute and Form 4 does not change it; mail your petition on time even if Form 4 is not perfect.
Can a corporation file Form 4 without a lawyer?
No. Corporations and most entities must be represented by counsel admitted to the Tax Court bar under Rule 60, and the admitted representative signs Form 4.
What happens if my SSN appears on a public filing by mistake?
Yes, you should act fast: file a motion to seal under Rule 27, and the Clerk will redact or replace the public version, often within a day.
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