How to Fill Out Tax Court Form 13 (w/Examples) + FAQs

You fill out U.S. Tax Court Form 13, the Entry of Appearance, by typing the docket number, case caption, and signing counsel’s full identifying information into the official PDF, then filing it through the DAWSON electronic filing system before any substantive participation in the case. Form 13 is the document a licensed practitioner uses to officially enter a U.S. Tax Court case as counsel of record, and it triggers all of the duties and powers set out in Tax Court Rule 24.

If you skip this filing or fill it out wrong, the Court will not recognize you as counsel, your motions can be stricken, and your client can lose default protections. The American Bar Association reports that roughly 69% of Tax Court petitioners appear pro se, so the moment a lawyer steps in with a clean Form 13, the case dynamics shift fast.

Here is what you will learn in this guide:

📝 How to complete every line of Form 13 without triggering a rejection notice
⚖️ How Tax Court Rule 24 governs entry, withdrawal, and substitution of counsel
💻 How to e-file through DAWSON and avoid the most common upload errors
👥 How Form 13 works alongside Form 5 (Substitution), Form 7 (Notice of Election of Small Tax Case), and Form 8 (Subpoena)
🚫 The seven costliest mistakes that get attorneys sanctioned, defaulted, or removed from the case

What Form 13 Actually Is

U.S. Tax Court Form 13 is titled Entry of Appearance, and it is the official document a practitioner files to tell the Court, the IRS, and the petitioner that the practitioner now represents a party in a docketed case. The form is short, but it carries weight because it is the moment counsel becomes the attorney of record under Rule 24(a)(2). Once filed, every order, notice, and decision flows to that attorney, and the attorney owes a duty of candor and diligence to the Court under Rule 201.

The plain-English version is that Form 13 is the Tax Court’s way of saying, “We now have a lawyer on this case, and we will hold that lawyer responsible.” If you ignore the form and just start filing motions, the Clerk’s office will return your papers unfiled. The consequence is missed deadlines, which in a deficiency case under IRC §6213 can mean a default decision against your client for the full amount the IRS proposed.

A common misconception is that signing a petition automatically enters counsel of record. It does not. The signature on the petition is treated as a one-time appearance for the petition itself, and the Court will still require a stand-alone Form 13 to recognize you for the rest of the case under Rule 24(a)(3).

A real-world example helps: imagine Maria Delgado, a CPA admitted to practice before the Tax Court, who drafts and signs a petition for her client. Maria assumes she is counsel of record, but she never files Form 13. When the IRS files an Answer, the Clerk sends it to the petitioner’s home address, not to Maria’s office, and Maria misses the Rule 37 deadline to reply to affirmative allegations. That single missed step can deem the IRS’s allegations admitted.

Who May File Form 13

Only individuals admitted to practice before the U.S. Tax Court may file Form 13, and admission is governed by Rule 200. That group includes attorneys in good standing with any state or D.C. bar, plus non-attorneys who pass the Court’s written admission exam. The Court keeps a roster of every admitted practitioner, and each one receives a unique Tax Court Bar Number.

If you are not admitted, filing Form 13 is the unauthorized practice of law before a federal court. The consequence can include referral to the practitioner’s state bar, civil penalties under 28 U.S.C. §1654, and immediate striking of every paper you filed. A common misconception is that an IRS Enrolled Agent or CPA license alone allows entry. It does not. Tax Court admission is a separate credential.

Picture James O’Hara, an enrolled agent who passed the IRS Special Enrollment Exam but never sat for the Tax Court non-attorney exam. James files Form 13 thinking his EA card is enough. The Clerk’s office rejects the filing, and his client loses two weeks of preparation time before the Branerton conference deadline under Rule 70(a)(1).

When Form 13 Is Required

Form 13 is required any time a practitioner enters a docketed case after the petition is filed, including substitutions, additions of co-counsel, and appearances after a withdrawal. The Court treats every change in representation as a formal event that must be on the docket. If you forget, the Court will continue routing mail to the prior address, which can blow statutory deadlines.

The consequence of filing late is concrete. Under Rule 25, if a motion is due 30 days from service and you never received service because your appearance was not on file, the Court can still treat the deadline as running. A common misconception is that calling the Clerk’s office to “let them know” is enough. It is not. Only a filed Form 13 controls the docket.

Line-by-Line Walkthrough of Form 13

The current version of Form 13 is a one-page fillable PDF with seven distinct fields. Each field has a precise purpose, and a mistake in any one of them can cause the Clerk to reject the filing under Rule 23. Below is the field-by-field guide, with the why and the consequence spelled out for each.

Field 1 — Case Caption

The case caption is the top block that names the parties, typically “[Petitioner Name], Petitioner v. Commissioner of Internal Revenue, Respondent.” The caption must match the petition exactly, including punctuation and the spelling of every name. The Clerk uses the caption to match the filing to the correct docket, and any mismatch routes the document to a manual review queue.

If you abbreviate, drop a middle initial, or use a trade name instead of the legal name, the Clerk can reject the filing. The consequence is a delay of three to ten business days while the office contacts you to correct the record. A common misconception is that the Court will “figure it out.” It will not. DAWSON uses exact-match logic on captions.

For example, Sunrise Bakery LLC v. Commissioner is not the same as Sunrise Bakery, LLC v. Commissioner in the DAWSON index. Counsel for Priya Shah, owner of Sunrise Bakery, learns this the hard way when her Form 13 sits unprocessed for a week because of the missing comma.

Field 2 — Docket Number

The docket number is the unique case identifier the Court assigns when the petition is filed, formatted like “12345-25” or “12345-25S” for small tax cases. You must include the full number plus any suffix, because the suffix tells the Court which procedural track applies under Rule 170 (small tax case rules).

The consequence of an incorrect docket number is that the filing posts to the wrong case or no case at all, which can mean missed service on the other side. A common misconception is that the suffix is optional. It is not. The “S” suffix changes the appealability of the final decision under IRC §7463(b), and the Court relies on it for routing.

Field 3 — Counsel’s Typed Name and Signature

You type your full legal name as it appears on your Tax Court admission record, and you sign in the signature block. The Court matches the typed name to its bar roster, so nicknames or shortened forms can cause a mismatch. The signature can be a typed “/s/ [Name]” under Rule 23(a)(3) when filed through DAWSON.

If the names do not match, the Clerk treats the filing as unsigned, and an unsigned filing is a nullity. The consequence is the same as never filing at all, which can mean a default judgment if a deadline passes. A common misconception is that wet-ink signatures are required. They are not, as long as you e-file through DAWSON with your verified practitioner account.

Field 4 — Tax Court Bar Number

Every admitted practitioner receives a Tax Court Bar Number when admission is granted under Rule 200(c). The number is permanent and is used on every filing for the rest of your career. You can look it up through the Court’s practitioner search tool inside DAWSON.

Leaving the field blank or using a state bar number instead will cause the filing to bounce. The consequence is the same delay as a caption error, plus a possible note in your practitioner file if the mistake repeats. A common misconception is that the IRS Centralized Authorization File (CAF) number works here. It does not, because CAF numbers govern IRS administrative practice, not Tax Court practice.

Field 5 — Mailing Address, Phone, and Email

The address you list becomes the service address for everything the Court and the IRS send. You must list a physical mailing address, a working phone number, and the email tied to your DAWSON account. Under Rule 21(b)(1), service on counsel of record is service on the client.

If the email bounces or the address is stale, you can miss orders, trial notices, and settlement offers. The consequence is severe because the Court can proceed without you. A common misconception is that updating your firm website is enough. It is not. You must file a separate notice of change of address under Rule 21(b)(4).

Imagine David Kim, a partner at a small tax firm, who moves offices and forgets to update his Tax Court address. The trial notice for his client’s $480,000 deficiency case goes to the old address, and David shows up the day after the calendar call. The Court can dismiss the case for failure to prosecute under Rule 123(b).

Field 6 — Statement of Representation

The body of the form contains a short statement that reads, in substance, “The undersigned, being duly admitted to practice before the United States Tax Court, hereby enters an appearance for [Petitioner Name] in the above-entitled case.” You fill in the petitioner’s name exactly as it appears in the caption.

If the petitioner’s name in the statement does not match the caption, the Clerk treats the form as ambiguous. The consequence is rejection and a request for a corrected filing. A common misconception is that you can list multiple petitioners on a single Form 13 by separating them with commas. You can if they are co-petitioners on the same docket, but you must list each name in full.

Field 7 — Date

The date you sign and file the form is the effective date of your appearance. Backdating is prohibited and can constitute a misrepresentation to the Court under Rule 33(b). Use the date you actually upload the filing in DAWSON.

The consequence of a backdated form is a possible Rule 33 sanction, which can include monetary penalties and referral to your state bar. A common misconception is that the date can be the date you were retained. It cannot. The retention date is private; the filing date is public and controlling.

How to E-File Form 13 Through DAWSON

The Court’s electronic filing system is called DAWSON, which stands for Docket Access Within a Secure Online Network. Every admitted practitioner must e-file through DAWSON for any case filed on or after the system’s launch in late 2020, per Administrative Order 2020-04. Paper filings are accepted only in narrow circumstances, such as documents under seal.

To file, you log into your verified practitioner DAWSON account, open the docket, choose “File a Document,” select “Entry of Appearance” from the drop-down, and upload the completed PDF. DAWSON time-stamps the filing in Eastern Time, and the cutoff for same-day filing is 11:59 p.m. ET under Rule 22(d).

If you upload the wrong document type or pick the wrong event code, the filing posts but is mis-indexed. The consequence is that opposing counsel and the Court may not see it, and you may miss the next deadline. A common misconception is that DAWSON automatically serves opposing counsel. It does, but only if the event code is correct and the case has at least one party with a verified e-service address.

Step-by-Step DAWSON Upload

The upload itself takes about five minutes once you have the PDF ready. The steps are:

Log into DAWSON using your practitioner credentials and two-factor code.
Search the docket number, open the case, and click “File a Document.”
Choose “Entry of Appearance” under the “Appearance and Representation” category.
Upload the signed PDF, confirm the filer is the same person named in the document, and submit.
Save the Notice of Receipt email DAWSON sends, because it is your proof of filing under Rule 22(d)(1).

If you skip the Notice of Receipt, you have no proof the Court received the filing. The consequence in a disputed deadline situation is that the Court will rely on its own docket time stamp, which may differ if you uploaded at 11:58 p.m. and the file finished processing at 12:01 a.m.

Paper Filing Exceptions

In a few situations, you must file Form 13 on paper. Those include cases sealed under Rule 27, filings by petitioners who are not represented and not eligible for DAWSON, and emergencies when DAWSON is down. Paper filings go to the Clerk’s office at 400 Second Street NW, Washington, D.C. 20217.

The consequence of paper filing when e-filing is required is that the Clerk can reject the document under Administrative Order 2020-04. A common misconception is that paper is “always allowed as a backup.” It is not. Once you are an admitted practitioner, DAWSON is mandatory unless the Court grants leave for paper filing in a specific motion.

Three Common Scenarios

Below are the three most common fact patterns where Form 13 controls the outcome, each with the trigger and the outcome spelled out.

Scenario 1 — New Counsel After a Pro Se Petition

Trigger	Outcome
Pro se petitioner files petition; attorney is retained 60 days later before the IRS Answer is filed.	Attorney files Form 13 only; no Form 5 needed because there is no prior counsel to substitute.
Attorney files Form 13 and a motion to extend time to respond to an upcoming order.	Court routes all future notices to the new attorney’s DAWSON email under Rule 21(b)(1).
Attorney forgets to file Form 13 and only files the motion.	Clerk strikes the motion as filed by a non-party because the attorney is not yet of record.

Scenario 2 — Substitution of Counsel Mid-Case

Trigger	Outcome
Original counsel withdraws via Form 5 (Substitution of Counsel) signed by both attorneys and the client.	New counsel files Form 13 the same day to maintain continuous representation.
Both forms filed together through DAWSON.	Docket updates instantly; no gap in service or deadlines.
New counsel files Form 13 but no Form 5 is filed by prior counsel.	Both lawyers remain on the docket, and all notices go to both, which can cause conflicting motions.

Scenario 3 — Adding Co-Counsel for Trial

Trigger	Outcome
Lead counsel asks a trial specialist to co-try a $2 million deficiency case.	Co-counsel files a separate Form 13; lead counsel does not refile.
Co-counsel includes a Tax Court Bar Number and DAWSON-verified email.	Both lawyers receive all e-service; either can sign filings under Rule 24(a).
Co-counsel uses a state bar number instead of a Tax Court Bar Number.	Clerk rejects the Form 13, and co-counsel cannot appear at trial.

Named Examples in Practice

Concrete examples make the rules stick. The three below show how Form 13 plays out for real clients with real money on the line.

Elena Vasquez, a self-employed graphic designer, files a pro se petition challenging a $42,000 deficiency tied to disallowed home-office deductions under IRC §280A. Two months later, she hires attorney Marcus Chen through a low-income taxpayer clinic. Marcus files Form 13 on a Monday, and on Tuesday he files a stipulation motion under Rule 91. Because his Form 13 is on the docket, the IRS counsel emails him directly, and the case settles within 90 days for $7,800.

Robert Tanaka, the CFO of a closely held S-corporation, faces a $1.2 million deficiency over disputed reasonable compensation under IRC §162(a)(1). His original counsel, Lisa Park, withdraws after a fee dispute. New counsel Anika Patel files Form 13 and a Form 5 the same day. Because both forms post simultaneously, the trial calendar set under Rule 131 is not disturbed, and Anika has time to prepare.

Greg Whitaker, a retired schoolteacher, elects small tax case treatment under Rule 171 for an $18,000 dispute. His attorney, Hannah Liu, files Form 13 with the “S” docket suffix correctly included. When the IRS files a motion to remove the small tax case designation, Hannah opposes it under IRC §7463(d), and because her appearance is properly on file, she receives the motion in time to respond.

Mistakes to Avoid

Form 13 is short, but the failure modes are real. Below are the most damaging mistakes practitioners make.

Filing Form 13 without first being admitted under Rule 200, which leads to outright rejection and possible bar referral.
Using a state bar number instead of a Tax Court Bar Number, which causes the Clerk to bounce the filing.
Omitting the “S” suffix on a small tax case docket number, which can route the filing to the wrong procedural track.
Backdating the form to match a retention agreement, which violates Rule 33(b) and can trigger sanctions.
Listing a stale or non-monitored email, which causes missed trial notices and possible dismissal under Rule 123(b).
Filing Form 13 without a paired Form 5 when substituting for prior counsel, which leaves both lawyers on the docket and creates conflicting service.
Uploading the form under the wrong DAWSON event code, which mis-indexes the filing and prevents automatic e-service to the IRS.
Signing the form for another attorney without explicit written authorization, which can constitute the unauthorized practice of law.
Forgetting to file a notice of change of address after moving offices, which causes service failures under Rule 21(b)(4).

Do’s and Don’ts for Form 13

Do’s

Do verify your Tax Court Bar Number in DAWSON before filing, because a typo means rejection.
Do match the case caption character-for-character to the petition, because exact-match logic governs docket routing.
Do file Form 13 the same day you are retained, because every day of delay is a day of missed service.
Do save the DAWSON Notice of Receipt, because it is your only proof of timely filing under Rule 22(d)(1).
Do pair Form 13 with Form 5 when replacing prior counsel, because the docket must reflect a clean handoff.

Don’ts

Don’t file Form 13 if you are not admitted, because doing so is the unauthorized practice of law before a federal court.
Don’t use your CAF number or state bar number, because the Court will treat the filing as unsigned.
Don’t backdate the signature line, because misrepresentation to the Court under Rule 33(b) is sanctionable.
Don’t assume the Clerk will fix small caption errors, because DAWSON’s matching engine is automated.
Don’t forget to update your address after moving, because service on a stale address still counts as service.

Pros and Cons of Filing Form 13 Early

Pros

Early filing puts you on the docket for every IRS Answer and motion, which protects your client from procedural defaults.
It gives you immediate access to DAWSON case documents, which speeds up case strategy and discovery prep under Rule 70.
It signals to IRS counsel that the case is being managed, which often accelerates Branerton settlement talks.
It creates a clear chain of representation, which is helpful for fee agreements and malpractice insurance audits.
It locks in your service address from day one, which reduces the risk of missed trial notices.

Cons

Early entry starts the clock on your duty of candor and diligence under Rule 201, even before you have full case facts.
It commits you to every deadline in the case, including any motion deadlines already pending.
It can complicate withdrawal later, because Rule 24(c) requires Court approval to withdraw once you are of record.
It makes you the default contact for all IRS settlement communications, which can be a workload burden in multi-case dockets.
It can create conflict-of-interest exposure if you later learn of a related case in your firm.

How Form 13 Interacts with Other Tax Court Forms

Form 13 does not stand alone. The Tax Court has a small family of forms that work together, and understanding the interaction prevents docketing mistakes.

Form 5 — Substitution of Counsel is filed when one practitioner replaces another. The new lawyer files Form 13, and both lawyers (plus the client) sign Form 5. Without Form 5, the prior lawyer stays on the docket, which can cause conflicting filings.

Form 7 — Notice of Election of Small Tax Case Procedure is used to elect simplified procedures under IRC §7463. It does not replace Form 13 but changes the procedural track, so counsel must enter appearance via Form 13 regardless of the election.

Form 8 — Subpoena is used to compel witness testimony or documents. Only counsel of record can issue a subpoena under Rule 147, so Form 13 must be on file first.

Withdrawal After Entry

Once you file Form 13, you cannot simply walk away. Rule 24(c) requires you to file a motion to withdraw, supported by good cause and proof of notice to the client. The Court can deny the motion if withdrawal would prejudice the case, especially close to a trial date set under Rule 131.

The consequence of failing to withdraw properly is that you remain counsel of record and are personally responsible for every deadline. A common misconception is that the client’s signature on a Form 5 alone is enough. It is not. The Court still must grant leave when no substituting attorney appears.

Recap of Key Rulings

Several Tax Court memorandum opinions show how Form 13 issues play out. In Pietanza v. Commissioner, 92 T.C. 729 (1989), the Court emphasized that counsel of record bears responsibility for receiving notices, even when the client also receives them. In Tinnerman v. Commissioner, T.C. Memo. 2010-150, the Court declined to vacate a dismissal where counsel claimed not to have received a notice that was sent to the address on his appearance form.

The lesson is that the address and email in Field 5 are not technicalities. They are the legal service address. The consequence of treating them casually is the loss of the case on procedural grounds, regardless of the merits.

State and Federal Interplay

The U.S. Tax Court is a federal Article I court, and its rules are entirely federal, so state law does not control practice before it. However, your underlying state bar license is what makes you eligible to seek admission under Rule 200(a)(2). If your state license lapses or is suspended, your Tax Court admission can be suspended too.

A few states impose additional reporting duties when an attorney files in federal court. California, for example, requires reporting under Cal. Rule of Prof. Conduct 8.5 when an attorney accepts federal representation. The consequence of ignoring a state-level reporting rule is a state bar inquiry, even if the Tax Court itself has no issue.

The interplay matters most at withdrawal. State ethics rules on client communication, file return, and fee refunds layer on top of Rule 24(c). A common misconception is that the federal motion to withdraw discharges all state duties. It does not.

FAQs

Is Form 13 the same as the petition?

No. The petition begins the case and is a separate form. Form 13 is filed later by counsel to formally enter appearance and become the attorney of record under Rule 24.

Can a non-attorney file Form 13?

Yes, but only if the non-attorney has passed the Tax Court admission exam and holds a Tax Court Bar Number under Rule 200(a)(3). Otherwise, filing is unauthorized practice.

Do I need to pay a fee to file Form 13?

No. There is no filing fee for Form 13. The only Tax Court filing fee is the $60 petition fee under Rule 20(b), paid by the petitioner when the case starts.

Can I file Form 13 on paper?

No, in almost all cases. Admitted practitioners must e-file through DAWSON per Administrative Order 2020-04, with limited exceptions for sealed filings or system outages.

Does Form 13 cover multiple cases?

No. Each docketed case requires its own Form 13. Even consolidated cases under Rule 141 need a separate appearance per docket.

Can I withdraw after filing Form 13?

Yes, but only by motion under Rule 24(c), with proof of notice to the client and Court approval. The Court can deny if withdrawal would harm the case.

Is a wet-ink signature required?

No. A typed “/s/ [Name]” signature is sufficient when filing through DAWSON under Rule 23(a)(3), as long as you file from your verified practitioner account.

Does filing Form 13 waive any client privileges?

No. Filing Form 13 only enters appearance; it does not affect attorney-client privilege or work-product protection, which remain governed by federal common law.

Can I file Form 13 before the petition is filed?

No. There must be a docketed case for the form to attach to. If you draft and sign the petition, that single document includes your appearance for that filing only.

Does Form 13 apply in Collection Due Process cases?

Yes. CDP cases under IRC §6330 are docketed in the Tax Court, so counsel must file Form 13 to appear, just like in a deficiency case.

Can I file Form 13 for an innocent spouse case?

Yes. Stand-alone innocent spouse cases under IRC §6015(e) are Tax Court cases, and Form 13 is the required vehicle for counsel to enter appearance.

What happens if I list the wrong docket number?

No filing is processed. DAWSON’s matching engine rejects the upload, and you must refile with the correct number, which can cost you days if a deadline is close.

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