Find the right kind of authority.
A source is useful when you know what question it can answer. Explore the original text, understand its role, and record the version you used.
Identify the role
Statutory text, regulations, judicial decisions, published guidance, individualized advice, and staff procedures perform different jobs. A simple numeric ranking hides those differences.
Check the year and status
Separate tax year, text date, publication date, and effective or applicability date. Look for amendments, supersession, revocation, and later judicial history.
Weigh the actual reasoning
Facts, jurisdiction, document type, contrary authority, and the question being asked matter. The penalty substantial-authority framework is distinct from binding precedent.
01 / Statutes & legislative contextU.S. Code: search and browse
Use it to
Choose Title 26 and the relevant section. Read the operative text together with definitions, cross-references, source notes, and amendment notes.
Do not infer
The displayed text must still be matched to the transaction date, tax year, and effective-date provisions. A current section is not automatically the version governing an older year.
02 / Statutes & legislative contextOLRC currency and updating
Use it to
Check the public-law cutoff for the online Code and the currency information displayed on individual sections.
Do not infer
A retrieval date tells you when you visited. It does not identify when every provision became applicable or establish that no later legislation exists.
03 / Statutes & legislative contextOLRC classification tables
Use it to
Move between a newly enacted public law and the Code sections it affects. Tables are available in public-law order and Code order.
Do not infer
The tables cover provisions classified to the Code. Read the actual enactment for uncodified effective dates, transition rules, and other provisions.
04 / Statutes & legislative contextGovInfo public and private laws
Use it to
Find the enacted slip law and inspect the actual amendment language, effective dates, and transition provisions.
Do not infer
An enacted law is different from a bill or a summary. A publication date and an effective date can differ; read the specific provision.
05 / Statutes & legislative contextJCT Bluebook: Public Law 119–21
Use it to
Use JCS-1-26 for the Joint Committee staff explanation of the tax provisions of Public Law 119–21. The publication page also identifies its errata.
Do not infer
A staff explanation is not the enacted statutory text. Distinguish a post-enactment Bluebook from contemporaneous committee reports, and verify the law and later developments.
06 / Statutes & legislative contextU.S. income tax treaties: country index
Use it to
Locate treaty texts, protocols, and Treasury explanations by country. Follow the links to the particular treaty documents.
Do not infer
A country appearing in the index does not establish an available benefit. Check residence, the relevant article, saving clauses, limitations, effective dates, and suspension or termination notices.
07 / Regulations & rulemakingeCFR: current Title 26 regulations
Use it to
Read Treasury regulations with internal cross-references, source citations, amendment information, and the displayed currency dates.
Do not infer
eCFR is continuously updated and is not the official annual legal edition. Check applicability, effective dates, later changes, and relevant judicial treatment rather than assuming a current rule resolves every year.
08 / Regulations & rulemakingeCFR historical versions and comparison
Use it to
Learn to select a point-in-time version and compare two dates. Use the timeline when researching a transaction from an earlier period.
Do not infer
A historical text snapshot does not by itself decide the tax-year applicability of a rule. Read the rule’s own applicability and transition provisions.
09 / Regulations & rulemakingGovInfo: annual CFR editions
Use it to
Consult the official annual CFR publication and archived editions. Title 26 belongs to the April 1 revision cycle.
Do not infer
An annual edition is a dated publication, not a live consolidation through today. Later Federal Register amendments may need to be read with it.
10 / Regulations & rulemakingFederal Register: IRS rulemaking
Use it to
Find proposed and final rules, Treasury Decisions, corrections, preambles, and statements of effective or applicability dates. Each item links to an official PDF.
Do not infer
Identify the document type before using it. A proposed rule is not simply a final rule; any permitted reliance must be checked in the actual guidance. The preamble and operative regulatory text serve different roles.
11 / IRS guidance & adviceInternal Revenue Bulletin archive
Use it to
Locate published revenue rulings, revenue procedures, notices, and announcements in their original bulletin context, including citations and later references.
Do not infer
Identify the particular item’s function and status. A revenue procedure may concern a filing method or safe harbor; a notice may provide interim guidance. Check modification, supersession, and revocation.
12 / IRS guidance & adviceIRS guide to the types of guidance
Use it to
Learn the distinctions among regulations, revenue rulings, revenue procedures, private letter rulings, technical advice memoranda, and notices.
Do not infer
This primer is an orientation tool. It does not establish that a particular document remains current or that another taxpayer can rely on a private ruling.
13 / IRS guidance & adviceWritten determinations: PLRs, TAMs, and CCAs
Use it to
Search released taxpayer-specific rulings, technical advice, and Chief Counsel advice by number, subject, or Uniform Issue List Code.
Do not infer
Read the document’s own disclaimer and §6110(k)(3). A ruling issued to someone else is not precedent for your case; released reasoning can still help identify issues and other authorities to investigate.
14 / IRS guidance & adviceIRS FOIA Library: counsel advice and reference material
Use it to
Find collections of legal advice, actions on decisions, settlement guidance, staff manuals, and training or reference materials.
Do not infer
FOIA disclosure is an access mechanism, not a guarantee of precedential status. Classify each document before using its reasoning or procedural description.
15 / Administration & explanationsInternal Revenue Manual
Use it to
Study the IRS’s internal organization and procedures for examination, collection, appeals, processing, and published guidance. Record the subsection’s revision date.
Do not infer
Staff instructions are not a substitute for statutes or regulations. Do not infer an independently enforceable taxpayer right merely because a manual describes an internal procedure.
16 / Administration & explanationsAudit Techniques Guides
Use it to
Learn industry terminology, common examination issues, records examiners may consider, and the context in which tax questions arise.
Do not infer
These are examination aids, not new tax law. Check the guide’s publication date and verify technical conclusions against current authorities; the IRS cautions that later changes can affect accuracy.
17 / Administration & explanationsPublication 541: partnership orientation
Use it to
Use the topic outline and examples to find vocabulary and identify related Code provisions, forms, and research questions about partnerships.
Do not infer
A plain-language publication is not a comprehensive legal opinion or a substitute for controlling authority. Its revision year and assumptions matter.
18 / Cases, opinions & ordersDAWSON: public case and opinion search
Use it to
Search Tax Court cases, opinions, and orders. Use the docket record to keep related documents and procedural context together.
Do not infer
Public electronic access is not the complete litigation file in every case. A docket entry is not necessarily a merits opinion, and sealed material is not publicly available.
19 / Cases, opinions & ordersTax Court: how to find an opinion
Use it to
Use keyword, date, judge, docket, and opinion-type filters. Read the facts, issue, reasoning, and holding rather than relying on the case caption.
Do not infer
Identify the opinion type and later judicial history. Precedential effect and controlling jurisdiction require analysis; a matching keyword does not establish a matching legal result.
20 / Cases, opinions & ordersTax Court: today’s orders
Use it to
Follow publicly released orders and inspect the case docket when studying procedural developments or locating an order cited elsewhere.
Do not infer
An order may address scheduling, evidence, jurisdiction, or another procedural issue. Do not treat every order as a published merits opinion or a general rule for other taxpayers.
21 / Cases, opinions & ordersGovInfo: selected federal court opinions
Use it to
Research opinions from participating appellate, district, bankruptcy, and certain national courts. The collection is useful when a tax issue appears outside the Tax Court.
Do not infer
Coverage is selective and may be incomplete. This is not a complete docket database. A district-court or Court of Federal Claims refund dispute also has its own jurisdictional and procedural requirements.
22 / Cases, opinions & ordersSupreme Court opinions
Use it to
Read the Court’s opinions and identify the majority or principal opinion, concurrences, dissents, and the publication stage.
Do not infer
A syllabus, dissent, or opinion relating to an order is not interchangeable with the Court’s holding. Identify the precise issue decided and subsequent developments.
23 / How to evaluate a source§6110(k)(3): written determinations and precedent
Use it to
Read the statutory rule concerning the precedential status of written determinations, including its qualifications.
Do not infer
Nonprecedential does not mean a document contains no useful reasoning. It means you must not convert someone else’s individualized determination into precedent for your own facts.
24 / How to evaluate a source§1.6662-4(d): substantial-authority framework
Use it to
Study which types of material can be considered and how relevance, persuasiveness, contrary authority, and later developments affect weight in this penalty context.
Do not infer
This is not a universal binding-precedent ladder. Material considered in the substantial-authority analysis does not thereby become binding law; the framework has its own conditions and exceptions.
No matching sources. Try a shorter term or another category.
Does partnership borrowing increase my basis?
Follow an issue across sources instead of searching for a sentence that confirms a preferred answer. The example deliberately separates legal classification from arithmetic.
Frame the issue before searching
Ask: “Does this change in the partner’s share of partnership liabilities affect outside basis?” Record the tax year, transaction date, opening basis, liability documents, and what changed. A bank balance or ownership percentage alone does not determine the liability allocation.
Read the statute and identify the missing factual determination
Section 752(a) treats an increase in the relevant liability share as a money contribution; §752(b) treats a decrease as a money distribution. That direction does not determine the amount of the partner’s share. Record the rule and the unresolved classification separately.
Move to the regulations that address the unresolved question
Read §1.752-1 for definitions and framework, then the applicable liability-allocation rules. Recourse analysis under §1.752-2 examines economic risk of loss. A debt label or the existence of a guarantee is not a complete allocation calculation.
Use an explanation, then test only the arithmetic you have established
Publication 541 helps orient the vocabulary. If an independently determined liability-share increase is $10,000 and opening outside basis is $25,000, a stripped-down illustration gives $35,000 before other adjustments. That arithmetic does not decide whether the $10,000 allocation is legally correct or whether a loss is deductible.
Check time, contrary authority, and the conclusion’s limits
Record the Code currency date, regulation text date, effective and applicability provisions, and the actual facts relied on. Search relevant guidance and cases when the issue requires them. Preserve what is assumed, what is established, and what remains unresolved; a calculator result is not authority.
Leave a research trail someone else can follow.
- State the precise issue, material facts, tax year, and jurisdiction.
- Save the citation, source URL, version, and relevant effective/applicability language.
- Record supporting and contrary authorities, distinguishing facts, and unresolved assumptions.
- Separate the legal conclusion from a worksheet or calculator illustration.
Directory reviewed November 15, 2026. Links open the external source; no taxpayer facts are sent by these search filters.