Practices and Procedures · Requirements for Enrolled Agents
Tax shelters
tax year · reviewed 2026-08-18 · I. Ohu
“Tax shelter” is a defined term with a low threshold, and the definition makes the rest of this topic work. It requires no abuse, secrecy or offshore structure — only that a significant purpose of an arrangement be the avoidance or evasion of Federal income tax. Once that is true, disclosure obligations and penalty consequences follow that do not apply to ordinary planning.
The rule
The definition (IRC § 6662(d)(2)(C)(ii)). A tax shelter means a partnership or other entity, any investment plan or arrangement, or any other plan or arrangement, if a significant purpose of it is the avoidance or evasion of Federal income tax.
That definition does specific work in § 6662. The substantial-understatement penalty is normally reduced where the taxpayer had substantial authority for the position, or adequately disclosed it with a reasonable basis (§ 6662(d)(2)(B)). Section 6662(d)(2)(C)(i) provides that this reduction does not apply to any item attributable to a tax shelter. Disclosure does not save a shelter item.
Reportable and listed transactions (IRC § 6707A(c)). A reportable transaction is one about which information must be included with a return or statement because, under regulations prescribed under IRC § 6011, it is of a type the Secretary determines as having a potential for tax avoidance or evasion. A listed transaction is a reportable transaction the same as, or substantially similar to, one the Secretary has specifically identified as a tax avoidance transaction.
Material advisor disclosure (IRC § 6111). Each material advisor with respect to any reportable transaction must file a return identifying and describing the transaction, describing any potential tax benefits expected to result, and giving such other information as the Secretary prescribes, by the date the Secretary specifies.
A material advisor (§ 6111(b)(1)(A)) is any person who provides material aid, assistance, or advice with respect to organizing, managing, promoting, selling, implementing, insuring, or carrying out any reportable transaction, and who directly or indirectly derives gross income in excess of the threshold amount for it. The thresholds are in the figures table.
List maintenance (IRC § 6112). Each material advisor must — whether or not required to file a § 6111 return — maintain a list identifying each person with respect to whom the advisor acted as a material advisor, plus such other information as regulations require. The list must be made available to the Secretary for inspection upon written request, and the information retained for the period in the figures table. Where two or more persons would have to maintain the same list, regulations may provide that only one need do so (§ 6112(b)(2)).
Taxpayer penalty (IRC § 6707A). Any person who fails to include on a return or statement information about a reportable transaction required under § 6011 pays a penalty computed under § 6707A(b) — see the figures table for the percentage, the caps by transaction type and taxpayer type, and the floor.
Advisor penalty (IRC § 6707). A person required to file a § 6111 return who fails to file on time or files false or incomplete information pays the penalty in § 6707(b), which is a flat amount for a reportable transaction and a much larger, income-based amount for a listed transaction — escalating where the failure or act is intentional. See the figures table.
Current figures
| Item | Amount or rule | Authority |
|---|---|---|
| Material advisor gross-income threshold | $50,000 where substantially all the tax benefits go to natural persons, and $250,000 in any other caseTY2026 | IRC § 6111(b)(1)(B) |
| § 6112 list retention | 7 years, except as otherwise provided by regulation, with the list produced to the Secretary on written requestTY2026 | IRC § 6112(b)(1) |
| § 6707A taxpayer penalty | {fig:shelter.6707A_penalty} | IRC § 6707A(b) |
| § 6707 advisor penalty | $50,000, or for a listed transaction the greater of $200,000 or 50% of the gross income derived from the aid, assistance or advice before the return is filed — 75% where the failure or act is intentionalTY2026 | IRC § 6707(b) |
| Shelter definition | A significant purpose of avoidance or evasion of Federal income tax | IRC § 6662(d)(2)(C)(ii) |
How it works in practice
“Significant purpose” is the whole game. It is not “the principal purpose” and not “the sole purpose.” An arrangement can have a genuine commercial rationale, a real business, and real economic risk, and still be a tax shelter under § 6662(d)(2)(C)(ii) because tax avoidance was a significant purpose alongside those things. Note also what the definition reaches: a partnership or other entity, an investment plan or arrangement, or any other plan or arrangement. The third category is a catch-all — nothing turns on the legal form.
The consequence in § 6662 is severe and often missed. For an ordinary position, a taxpayer facing the substantial-understatement penalty can escape it with substantial authority, or with adequate disclosure plus a reasonable basis. Section 6662(d)(2)(C)(i) removes both routes for an item attributable to a tax shelter. Disclosing a shelter item on Form 8275 does not reduce the § 6662 penalty; nothing in § 6662(d)(2)(B) is available.
Reportable is not the same as listed. Every listed transaction is reportable, but most reportable transactions are not listed. “Listed” means the Secretary has specifically identified that transaction, or one substantially similar, as a tax avoidance transaction. The distinction drives the penalty amounts under both § 6707A and § 6707, which are several times larger for a listed transaction.
The material advisor test has two prongs, and both must be met. The conduct prong — material aid, assistance or advice as to organizing, managing, promoting, selling, implementing, insuring or carrying out the transaction — is broad, and “insuring” reaches parties who never touched the tax analysis. The income prong is a bright line: gross income in excess of the threshold, derived directly or indirectly. A practitioner whose fee falls below it is not a material advisor, whatever advice they gave.
Note which threshold applies. The lower figure applies where substantially all the tax benefits from the transaction go to natural persons; the higher figure applies in any other case. It is the identity of the benefit recipients, not of the advisor or the client, that selects the threshold.
Section 6112 is broader than § 6111 in one respect that is examinable. The list-maintenance duty applies to a material advisor whether or not that advisor was required to file a § 6111 return. A person can owe the list obligation without owing the disclosure return. And the list is not filed — it is maintained, produced on the Secretary’s written request, and retained for the statutory period.
Circular 230’s connection. Since the 2014 repeal of the covered opinion rules, Part 10 has no separate tax-shelter opinion regime. What remains is § 10.37(c)(2): where a practitioner knows or has reason to know their written opinion will be used by someone else to promote, market or recommend an entity, investment plan or arrangement a significant purpose of which is tax avoidance or evasion — the same formula — the reasonable practitioner standard applies with emphasis on the additional risk caused by the practitioner’s lack of knowledge of the particular taxpayer’s circumstances.
A real business with a significant tax purpose
A partnership acquires an operating equipment-leasing business. The business is genuine, the leases are real, and the partners expect an operating profit. The structure was chosen in preference to two simpler alternatives because it generates accelerated deductions the alternatives would not, and the memoranda circulated at formation give roughly equal weight to the operating case and the tax case.
Analysis. A tax shelter under IRC § 6662(d)(2)(C)(ii). The definition asks whether a significant purpose is the avoidance of Federal income tax, not whether it is the only or the dominant purpose. Real business substance does not displace the finding where the tax case was a co-equal driver of the structure. The practical consequence is that if an item attributable to the partnership produces a substantial understatement, neither substantial authority nor adequate disclosure with a reasonable basis will reduce the § 6662 penalty.
Two advisors, one threshold
Two enrolled agents advise on the same reportable transaction, whose tax benefits flow substantially all to individual investors. One is paid $61,000 for structuring advice; the other is paid $34,000 for implementation work.
Analysis. Only the first is a material advisor. Both satisfy the conduct prong of IRC § 6111(b)(1)(A)(i) — structuring is "organizing" and implementation work is "implementing" — but § 6111(b)(1)(A)(ii) also requires gross income in excess of the threshold amount, which here is the lower figure because substantially all the tax benefits go to natural persons. The second agent's fee is below it. The first owes the § 6111 return and, independently, the § 6112 list.
The list nobody filed
A material advisor concludes, on advice, that no § 6111 return is due for a particular reportable transaction because of the timing rules, and files none. He also keeps no list of the clients he advised, reasoning that the list requirement follows the return requirement.
Analysis. The second conclusion is wrong regardless of the first. IRC § 6112(a) applies to each material advisor "whether or not required to file a return under section 6111 with respect to such transaction." He must maintain a list identifying each person for whom he acted as a material advisor, make it available to the Secretary on written request, and retain the information for the statutory period.
“A significant purpose,” not “the principal purpose.” IRC § 6662(d)(2)(C)(ii) uses the lower standard. An arrangement with substantial business purpose can still be a tax shelter.
Disclosure does not cure a shelter item. Section 6662(d)(2)(C)(i) disapplies the whole of § 6662(d)(2)(B) — both the substantial-authority route and the disclosure-plus-reasonable-basis route.
The § 6112 list is owed even where no § 6111 return is. Section 6112(a) applies “whether or not required to file a return under section 6111.”
The threshold turns on who gets the benefits. The lower § 6111(b)(1)(B) figure applies where substantially all the tax benefits go to natural persons; the higher applies in any other case. It is not selected by the advisor’s or the client’s identity.
How this has changed
The current architecture dates from the American Jobs Creation Act of 2004 (Pub. L. 108-357). That Act rewrote § 6111 from a “tax shelter registration” regime into the material advisor disclosure regime, rewrote § 6112 into the material-advisor list requirement, replaced the old § 6707 with the current advisor penalty, and added § 6707A — the taxpayer-level penalty for omitting reportable transaction information.
Two earlier amendments still shape the § 6662 definition. The 1994 legislation (Pub. L. 103-465) restructured § 6662(d)(2)(C), and the Taxpayer Relief Act of 1997 (Pub. L. 105-34, § 1028(c)(2)) made the change that matters most: it substituted “a significant purpose” for “the principal purpose” in the shelter definition. That single substitution is why so many ordinary-looking arrangements fall inside the term today, and why the phrase recurs in Circular 230 § 10.37(c)(2).
The 2004 Act then amended § 6662(d)(2)(C) again (Pub. L. 108-357, § 812(d)), replacing a more complicated set of corporate and non-corporate rules — under which a non-corporate taxpayer could still get relief if it reasonably believed the treatment was more likely than not proper — with the flat rule now in force: subparagraph (B) simply does not apply to any item attributable to a tax shelter.
On the Circular 230 side, the significant change is a removal. T.D. 9668 (June 12, 2014) repealed the covered opinion rules, which had contained the elaborate tax-shelter opinion requirements. Study material describing those requirements is describing repealed law; what governs a practitioner’s written advice about a shelter today is the general standard in § 10.37, with the marketed-transaction emphasis in § 10.37(c)(2).
Exam focus
Know the definition cold: a partnership or other entity, any investment plan or arrangement, or any other plan or arrangement, where a significant purpose is the avoidance or evasion of Federal income tax (IRC § 6662(d)(2)(C)(ii)). The commonest distractor substitutes “the principal purpose.”
Know that § 6662(d)(2)(C)(i) removes both penalty-reduction routes for a shelter item — substantial authority and adequate disclosure with a reasonable basis.
Know the two prongs of material advisor: material aid, assistance or advice as to organizing, managing, promoting, selling, implementing, insuring or carrying out the transaction, and gross income above the threshold, with the lower threshold where substantially all the benefits go to natural persons.
Know that § 6112 list maintenance is independent of § 6111 filing, that the list is produced on written request rather than filed, and that listed transactions carry much larger penalties than other reportable transactions under both § 6707A and § 6707.
Check yourself
1. Which standard does IRC § 6662(d)(2)(C)(ii) use in defining a tax shelter? (A) The sole purpose is tax avoidance (B) The principal purpose is tax avoidance (C) A significant purpose is the avoidance or evasion of Federal income tax (D) The arrangement lacks economic substance Answer: C. The Taxpayer Relief Act of 1997 substituted “a significant purpose” for “the principal purpose,” so an arrangement with real business purpose can still be a tax shelter.
2. A taxpayer adequately discloses a position attributable to a tax shelter and has a reasonable basis for it. Does that reduce the substantial-understatement penalty? (A) Yes, disclosure plus reasonable basis always reduces it (B) Yes, if the shelter is not a listed transaction (C) No, § 6662(d)(2)(C)(i) disapplies § 6662(d)(2)(B) to any item attributable to a tax shelter (D) Only for a non-corporate taxpayer Answer: C. Neither the substantial-authority route nor the disclosure route is available for a shelter item; the non-corporate exception was removed in 2004.
3. Which two conditions must both be met for a person to be a material advisor under IRC § 6111? (A) Signing the return and deriving any fee (B) Providing material aid, assistance or advice as to the transaction, and deriving gross income above the threshold amount (C) Promoting the transaction and holding a PTIN (D) Filing a § 6112 list and deriving gross income above the threshold Answer: B. Section 6111(b)(1)(A) requires both the conduct prong and the gross-income prong; the conduct prong covers organizing, managing, promoting, selling, implementing, insuring or carrying out the transaction.
4. Must a material advisor who is not required to file a § 6111 return still maintain a § 6112 list? (A) No, the list follows the return requirement (B) Yes, § 6112(a) applies whether or not a § 6111 return is required (C) Only for listed transactions (D) Only if the Secretary requests it in advance Answer: B. The parenthetical in § 6112(a) says so expressly. The list is maintained, made available on written request, and retained for the statutory period.
5. What distinguishes a listed transaction from another reportable transaction? (A) A listed transaction involves a partnership (B) A listed transaction is one the Secretary has specifically identified as a tax avoidance transaction, or one substantially similar to it (C) A listed transaction always involves a material advisor (D) A listed transaction is disclosed on a different form Answer: B. Section 6707A(c)(2). The distinction drives substantially larger penalties under both § 6707A and § 6707.
Change log
- Initial publication from IRC §§ 6662(d)(2)(C), 6111, 6112, 6707 and 6707A.