Schedule B-1 is the disclosure attachment to Form 1065 that tells the IRS exactly which entities or individuals own 50% or more of a partnership’s profit, loss, or capital. You file it any time you answer “Yes” to question 2a or 2b on Schedule B of Form 1065, and you must apply the constructive ownership rules of IRC §267(c) before deciding whether a partner crosses the 50% line.
Skipping the form, or filling it out using only direct ownership, is one of the most common partnership filing errors. According to the IRS Data Book for Fiscal Year 2024, more than 4.5 million partnership returns are filed each year, and incomplete Schedule B disclosures are a leading trigger for partnership-level correspondence audits.
Here is what you will learn in this guide:
- 📋 How to read every line of Schedule B-1, Part I and Part II, without guessing.
- 🧮 How the Section 267(c) constructive ownership rules pull family members, trusts, and tiered entities into your 50% test.
- ⚠️ The penalty exposure under IRC §6698 and §6722 when Schedule B-1 is missing or wrong.
- 🏢 How tiered partnerships, husband-wife LLCs, trust partners, and foreign corporate partners change the answer.
- 🛠️ The mistakes, do’s, don’ts, and 10+ FAQs that resolve the real-world questions filers ask every season.
What Schedule B-1 Is and Why It Exists
Schedule B-1, formally titled Information on Partners Owning 50% or More of the Partnership, is an attachment to Form 1065. The IRS uses it to map the true ownership of a partnership when one or more partners cross the 50% threshold in profit, loss, or capital. The disclosure exists because direct ownership rarely tells the whole story.
Congress and Treasury built the rule on IRC §6031 and Treas. Reg. §1.6031(a)-1, which require partnerships to file complete returns. The IRS added Schedule B-1 in 2008 to close information gaps tied to abusive tax shelters and tiered partnership planning. The form is short, but the analysis behind it is not.
The consequence of ignoring Schedule B-1 is real. The IRS treats a missing schedule as an incomplete return, which can void the safe harbor that protects late filers and keep the statute of limitations open under IRC §6501. The Tax Court decision in Seaview Trading, LLC v. Commissioner reminded taxpayers that an incomplete partnership return may not start the assessment clock at all.
A common misconception is that small partnerships do not need Schedule B-1. The form applies to every domestic partnership filing Form 1065, regardless of revenue, when the 50% test is met. Even a two-member LLC taxed as a partnership can trigger it.
The Trigger: Schedule B Questions 2a and 2b
You only file Schedule B-1 when you answer “Yes” to either question 2a or 2b on Schedule B of Form 1065. Question 2a asks whether any entity owns, directly or indirectly, 50% or more of the partnership’s profit, loss, or capital. Question 2b asks the same about any individual or estate.
The phrase directly or indirectly is the entire game. You must run the Section 267(c) constructive ownership rules before you answer. If you only check the K-1 list, you will miss attribution from family members, trusts, corporations, and other partnerships.
The consequence of a wrong “No” answer is treble. First, the return is incomplete. Second, the partners’ Schedule K-1s may be deemed unfiled. Third, the BBA centralized audit regime under IRC §6221 may push adjustments to the partnership itself.
Who Must File and Who Is Exempt
Every domestic partnership that files Form 1065 must answer Schedule B questions 2a and 2b, and must attach Schedule B-1 if either answer is “Yes.” Foreign partnerships filing Form 8865 follow a parallel disclosure on Schedule A of that form, not Schedule B-1. Single-member LLCs that are disregarded entities do not file Form 1065 at all.
There is no small-partnership carve-out. The old Revenue Procedure 84-35 penalty relief for partnerships of 10 or fewer eligible partners does not exempt you from filing the schedule itself. It only protects late-filing penalties when every partner has properly reported income.
A frequent misconception is that publicly traded partnerships escape the form. They do not. A PTP that has any 50% owner, including through a holding company chain, must still file Schedule B-1.
Schedule B-1 Walkthrough: Part I (Entities)
Part I of Schedule B-1 collects information on entity owners that hold 50% or more of profit, loss, or capital. An entity here means a corporation, partnership, trust, tax-exempt organization, or foreign government. You list each qualifying entity on its own line.
The form requires four data points per entity: name, employer identification number (EIN), country of organization, and maximum percentage owned in profit, loss, or capital. Maximum is the key word. If the entity owns 60% of capital but only 30% of profit, you report 60%.
The consequence of mixing up direct and constructive ownership in Part I is an automatic mismatch with the partner K-1 file. The IRS Business Master File cross-checks EINs, and a missing or wrong EIN can flag the return for CP259 notices.
A real-world example: Maria runs Coastal Holdings LLC, which owns 55% of Coastal Realty Partners LP. Coastal Holdings goes on Part I, line 1, with its EIN, “United States” as country, and 55% as the maximum percentage. Maria herself does not appear in Part I.
Column-by-Column Detail for Part I
Column (i) is the entity name. Use the legal name on the entity’s most recent tax return, not a DBA. Column (ii) is the EIN. If the entity is foreign and has no EIN, write “Foreign” or “Applied For” if an SS-4 is pending.
Column (iii) is the country of organization. Use the country where the entity was legally formed, not where it does business. A Delaware LLC owned by Cayman investors is still “United States.” Column (iv) is the maximum percentage owned in profit, loss, or capital, expressed to at least the nearest whole percent.
The consequence of rounding too aggressively is an under-disclosure. If true ownership is 50.4%, do not round down to 50%; report 50.4% or “50%” only when the actual figure equals 50.0%. The instructions to Form 1065 Schedule B-1 require the highest of the three measures.
Tiered Partnerships and Look-Through
Tiered structures require look-through analysis. If Partnership A owns 100% of Partnership B, and Partnership B owns 60% of your filing partnership, then Partnership A constructively owns 60% and must appear on Part I. You list both, because each holds 50% or more.
The consequence of stopping at the first tier is a classic audit issue. The Joint Committee on Taxation Bluebook on partnership reporting flagged tiered nondisclosure as a pattern in shelter cases. List every entity in the chain that meets the 50% test.
A common misconception is that you only list the “top” parent. You list every entity in the chain that meets 50% in profit, loss, or capital. Devon’s family office may have three layers, and all three may need their own Part I lines.
Schedule B-1 Walkthrough: Part II (Individuals and Estates)
Part II reports each individual or estate that owns 50% or more of the partnership in profit, loss, or capital, directly or constructively. The threshold and the maximum rule are the same as Part I. Trusts go in Part I, not Part II, because the IRS treats trusts as entities for this form.
The four data points are name, taxpayer identifying number (SSN or ITIN), country of citizenship, and maximum percentage owned. Country of citizenship matters for withholding under §1446 and FIRPTA reporting if the partner is foreign.
The consequence of putting an SSN in Part I, or an EIN in Part II, is a return reject or a downstream notice. Match the column to the partner type. If a partner is a single-member disregarded LLC, look through to the individual owner and report the human in Part II.
A real-world example: James and Linda Carter each own 30% of Carter Family Partners LLC. Under §267(c)(4) family attribution, James constructively owns Linda’s 30% and vice versa. Both report 60% on Part II, on separate lines, with their own SSNs.
Constructive Ownership Under Section 267(c)
Section 267(c) is the heart of Schedule B-1. It contains five attribution rules, and the Schedule B-1 instructions tell you to use all of them when answering questions 2a and 2b. The rules turn the 50% test into a chain-of-ownership exercise.
Rule one, entity attribution, treats stock or partnership interests held by a corporation, partnership, estate, or trust as owned proportionately by its owners or beneficiaries. Rule two, family attribution, treats interests owned by a spouse, brothers and sisters (whole or half blood), ancestors, and lineal descendants as owned by the individual.
Rule three is the chain rule, which re-applies the family and entity rules iteratively. Rule four, the partner rule, attributes interests held by one partner to another partner in the same partnership for purposes of certain tests. Rule five blocks double family attribution to avoid endless loops.
The consequence of ignoring §267(c) is the most common error on Schedule B-1. A husband-wife LLC that lists each spouse as a 50% direct owner often answers “No” to 2b and skips the form. That is wrong. Each spouse constructively owns 100% and both must be reported on Part II at 100%.
Trusts, Estates, and Disregarded Entities
A trust partner is reported in Part I as an entity, with the trust’s EIN. The trust’s grantor or beneficiaries are not reported individually unless they themselves cross 50% under §267(c). An estate is reported in Part II if it is an estate of a deceased individual, using the estate’s EIN.
A disregarded entity, such as a single-member LLC, is looked through to its sole owner for Schedule B-1. If the sole owner is a person, that person is reported in Part II. If the sole owner is a corporation, the corporation is reported in Part I.
The consequence of treating a disregarded LLC as the partner is a name-EIN mismatch with the K-1, which the IRS Modernized e-File system will flag. Priya’s PR Studio LLC is disregarded, so Priya, not the LLC, appears on Part II.
Three Common Filing Scenarios
Real partnerships rarely look like the textbook. The three scenarios below show the disclosure outcome under common ownership patterns.
| Ownership Pattern | Schedule B-1 Outcome |
|---|---|
| Two unrelated members, each 50% of an LLC | Both listed on Part II at 50%; question 2b answered “Yes.” |
| Husband and wife, each 50% direct, no other partners | Each listed on Part II at 100% under §267(c)(4) family attribution. |
| Holding LLC owns 80%, two unrelated individuals own 10% each | Holding LLC listed on Part I at 80%; Part II not triggered for the 10% owners. |
| Tiered Structure | Schedule B-1 Outcome |
|---|---|
| Parent Corp owns 100% of Sub LLC, Sub LLC owns 60% of filer | Parent Corp and Sub LLC both listed on Part I at 60%. |
| Trust owns 70% of filer; sole beneficiary is one child | Trust listed on Part I at 70%; child listed on Part II at 70% via §267(c). |
| Foreign corporation owns 55% of filer | Foreign Corp listed on Part I at 55%; country of organization is the foreign country. |
| Family-Controlled Structure | Schedule B-1 Outcome |
|---|---|
| Father 30%, Son 30%, Unrelated 40% | Father and Son each constructively own 60%; both listed on Part II. |
| Three siblings, 33.3% each | Each sibling constructively owns 100% under §267(c)(4); all three listed on Part II. |
| Grandparent 20%, Parent 20%, Child 20%, Unrelated 40% | Each family member constructively owns 60%; all three listed on Part II. |
Named Examples That Show the Rules in Action
Marcus owns 40% of Riverstone Partners LP, and his daughter Olivia owns 25%. Under §267(c)(4), Marcus constructively owns Olivia’s 25%, giving him 65%. Olivia constructively owns Marcus’s 40%, giving her 65%. Both go on Part II at 65%.
Anika is the sole beneficiary of the Patel Family Trust, which owns 70% of Lotus Capital LLC. The trust is reported on Part I at 70% with its EIN. Anika is reported on Part II at 70% because §267(c)(1) attributes the trust’s interest to her proportionately as a beneficiary.
Brightline Holdings Inc., a Delaware C corporation, owns 60% of Brightline Logistics Partners. Brightline Holdings goes on Part I at 60%. The shareholders of Brightline Holdings are not reported on Part II unless one of them owns more than 50% of Brightline Holdings and therefore constructively owns more than 30% of Brightline Logistics — which is below the 50% threshold and would not trigger Part II.
Step-by-Step: Completing Schedule B-1
Step one is to map every direct partner from your Schedule K-1 file. Note each partner’s profit, loss, and capital percentages from item J of the K-1. Identify the maximum of the three.
Step two is to run §267(c) attribution against every direct partner. Build a quick chart of family relationships, entity ownership chains, and trust beneficiaries. Re-apply the rules iteratively until no new partner crosses 50%.
Step three is to populate Part I for entities and Part II for individuals and estates that meet the threshold. Use the partner’s legal name and TIN exactly as it appears on their tax return. Step four is to attach Schedule B-1 to Form 1065 and answer Schedule B questions 2a and 2b “Yes” as appropriate.
Step five is to e-file through an authorized e-file provider or paper-file to the address listed in the Form 1065 instructions. E-filed returns are required for partnerships with more than 100 partners under Treas. Reg. §301.6011-3.
Filing Deadlines and Extensions
Form 1065, with Schedule B-1 attached, is due the 15th day of the third month after the close of the partnership’s tax year. For calendar-year partnerships, that is March 15, 2026, for the 2025 tax year. A six-month extension is available by filing Form 7004.
The consequence of missing the deadline is a penalty under IRC §6698 of $245 per partner, per month, for up to 12 months for tax years beginning in 2025. The penalty applies even if the partnership has no taxable income.
A common misconception is that an extension of time to file extends the time to assemble Schedule B-1. It does. But the schedule must be complete and accurate when you file the extended return. Late or wrong information triggers the same penalty exposure.
Amending a Return to Add Schedule B-1
If you discover a missing or incorrect Schedule B-1 after filing, you must amend. Partnerships subject to the BBA centralized partnership audit regime file an Administrative Adjustment Request on Form 8082. Partnerships that elected out of BBA file an amended Form 1065 with the “Amended Return” box checked.
The consequence of an unamended error is exposure to the §6722 penalty for failure to furnish correct information returns, which can reach $340 per K-1 for 2025 returns. Repeated or willful errors push the penalty higher.
Mistakes to Avoid on Schedule B-1
A short list of avoidable errors saves real money. Each mistake below ties to a specific consequence under the Code or the instructions.
- Skipping §267(c) family attribution between spouses, siblings, parents, and children, which causes a wrong “No” on question 2b and an incomplete return.
- Listing a disregarded LLC instead of its individual owner, which creates a name-TIN mismatch and a likely IRS CP162 notice.
- Reporting the lowest of profit, loss, or capital instead of the maximum, which under-discloses ownership and breaches the instruction.
- Forgetting to look through tiered partnerships beyond the first tier, which hides ultimate ownership the IRS can later reconstruct.
- Confusing trusts as Part II individuals, when the form requires trusts to appear in Part I as entities with their EIN.
- Reporting estimated percentages instead of using item J of the Schedule K-1, which creates internal inconsistency in the return.
- Leaving country of citizenship blank for U.S. individuals, which the IRS treats as a fillable defect that can delay processing.
- Failing to attach Schedule B-1 at all when answering “Yes” to question 2a or 2b, which voids return completeness under IRC §6031.
Do’s and Don’ts for Schedule B-1
The do’s and don’ts below come straight from the IRS Schedule B-1 instructions and from common practitioner experience.
Do’s:
- Do build a family tree and entity org chart before completing the form, because §267(c) attribution depends on relationships you may not see on the K-1 list.
- Do use the maximum of profit, loss, or capital, because the instructions require it and the IRS will catch a downward bias.
- Do match each partner’s legal name and TIN to their tax return exactly, because the IRS Business Master File matches on name control and TIN.
- Do file Schedule B-1 with the original return whenever possible, because amendments under BBA require Form 8082 and trigger more scrutiny.
- Do retain working papers showing your §267(c) analysis, because the IRS may request them on examination and the burden of proof is on the partnership.
Don’ts:
- Don’t assume small partnerships are exempt, because Rev. Proc. 84-35 only relieves penalties, not the filing duty itself.
- Don’t ignore foreign partners, because country of citizenship and country of organization columns drive §1446 withholding cross-checks.
- Don’t combine multiple partners on a single line, because the form is line-per-partner and combined entries trigger processing errors.
- Don’t list general partners just because they manage the partnership; list partners who meet the 50% ownership test.
- Don’t round down to 49% to dodge the threshold, because that misstatement can support a fraud penalty under IRC §6663 when intentional.
Pros and Cons of Strict Schedule B-1 Compliance
Treating Schedule B-1 as a high-priority disclosure has clear upside and limited downside. The list below shows both sides for partnerships and their advisors.
Pros:
- Strict compliance starts the assessment statute under §6501, giving the partnership finality after three years in most cases.
- Accurate disclosure reduces the chance of a CP162 notice and the cascade of penalty assessments that follow.
- Clean §267(c) workpapers support related filings such as Form 8990 interest limitation and Form 8082 administrative adjustments.
- Transparent ownership reporting helps lenders, investors, and buyers in due diligence, because Schedule B-1 lines up with cap-table disclosures.
- Consistent reporting reduces the risk of IRS partnership-level adjustments under the BBA centralized audit regime.
Cons:
- The §267(c) analysis is time-intensive, and some partnerships pay several billable hours each year for the workpaper file.
- Disclosing maximum ownership can surface family or trust relationships the partners would prefer to keep private from the IRS.
- E-file software sometimes mis-handles tiered ownership entries, requiring manual PDF attachments under Pub. 4163 procedures.
- Foreign partner disclosure can trigger downstream Form 8804 and Form 8805 withholding obligations.
- Errors are easy to repeat year over year, so a single misread of §267(c) can become a multi-year exposure if not caught early.
Penalties, Audits, and Court Rulings
Failure to file a complete Form 1065, including Schedule B-1, exposes the partnership to the §6698 penalty of $245 per partner per month for tax years beginning in 2025, capped at 12 months. Failure to furnish correct K-1 information triggers a separate §6722 penalty of up to $340 per K-1 for 2025.
The Tax Court in Seaview Trading, LLC v. Commissioner, 9th Cir. en banc 2023 held that delivering a partnership return to the wrong IRS office did not start the assessment clock. The case is a reminder that completeness and proper filing channel both matter for Schedule B-1 protection.
In Rafizadeh v. Commissioner, 150 T.C. No. 1 (2018), the court reinforced that information return defects can extend the statute of limitations under §6501(c)(8) when foreign reporting is involved. Schedule B-1’s foreign partner disclosure intersects with this rule.
The BBA centralized partnership audit regime under IRC §6221 makes the partnership itself liable for adjustments, including imputed underpayments tied to misreported ownership. Partnerships that elected out under §6221(b) still need accurate Schedule B-1 because the election itself depends on partner-type disclosure.
Key Entities, People, and Concepts
Several actors and concepts shape Schedule B-1 compliance. The Internal Revenue Service processes the form through the Modernized e-File system and the Ogden Submission Processing Center for paper returns. The Office of Chief Counsel drafts the technical instructions.
The Joint Committee on Taxation reviews legislative changes affecting partnership disclosure. The Treasury Inspector General for Tax Administration audits IRS handling of Form 1065 compliance, including Schedule B-1 mismatches. Practitioners interact with the Office of Professional Responsibility when Circular 230 issues arise from incorrect filings.
Core concepts include direct ownership, constructive ownership under §267(c), tiered partnerships, family attribution, entity attribution, the BBA audit regime, the TEFRA legacy regime for older years, and the §6031 completeness standard. Each connects to the others through the maximum ownership test.
State-Level Nuances After the Federal Filing
Federal Schedule B-1 is the controlling disclosure, but several states demand parallel reporting on their own partnership returns. California Form 568 and Schedule EO ask LLCs to identify owners with 50% or more interest, and California enforces with its own penalty in Revenue and Taxation Code §19172.
New York Form IT-204 requires identification of partners with material ownership and triggers IT-204-IP partner-level reporting. Texas franchise tax filings via Form 05-102 require disclosure of officers, directors, and 10% owners, which is a lower threshold than federal Schedule B-1.
The consequence of a state mismatch is a state-level audit notice that often expands into a federal review. Aligning federal and state ownership disclosure in one workpaper file reduces this risk. A common misconception is that state filings are independent. In practice, state revenue departments share data with the IRS under IRC §6103 information-exchange agreements.
FAQs
Is Schedule B-1 required for every partnership?
No. It is required only when the partnership answers “Yes” to question 2a or 2b on Schedule B of Form 1065, meaning at least one entity, individual, or estate owns 50% or more directly or constructively.
Do husband-wife LLCs always need Schedule B-1?
Yes. Family attribution under §267(c)(4) treats each spouse as owning the other’s interest, so each spouse constructively owns 100% and both must appear on Part II.
Does a single-member disregarded LLC partner go on Schedule B-1?
No. You look through the disregarded LLC to its individual or corporate owner and report that owner instead, using the owner’s legal name and TIN.
Are trusts reported on Part I or Part II?
Yes, on Part I. The IRS treats trusts as entities for Schedule B-1, so list the trust with its EIN, country of organization, and maximum ownership percentage.
Does Schedule B-1 use profit, loss, or capital percentage?
Yes, all three. You report the maximum of profit, loss, or capital, because the Schedule B-1 instructions require the highest of the three measures.
Can a partnership skip Schedule B-1 if it qualifies for Rev. Proc. 84-35 relief?
No. Rev. Proc. 84-35 only relieves the late-filing penalty for small partnerships; it does not waive the duty to attach Schedule B-1 when the 50% test is met.
Does an extension to file Form 1065 extend Schedule B-1?
Yes. A timely Form 7004 extension covers the entire return, including Schedule B-1, but the schedule must be complete and accurate when the extended return is filed.
Are foreign partners reported differently on Schedule B-1?
Yes. Foreign entities go on Part I with their country of organization, and foreign individuals go on Part II with their country of citizenship, which links to §1446 withholding reporting.
Does Schedule B-1 affect the BBA centralized audit regime?
Yes. Accurate Schedule B-1 disclosure supports both BBA partnership-level adjustments and any election out under §6221(b), because the election depends on eligible partner types.
Can incorrect Schedule B-1 entries trigger penalties?
Yes. IRC §6698 imposes per-partner monthly penalties for incomplete returns, and §6722 imposes per-K-1 penalties for incorrect information returns.
Does Schedule B-1 ever start or stop the statute of limitations?
Yes. Decisions like Seaview Trading confirm that incomplete partnership returns may not start the §6501 clock, so a missing Schedule B-1 can leave the year open indefinitely.
Is Schedule B-1 the same as Schedule B?
No. Schedule B is a series of yes/no questions inside Form 1065, while Schedule B-1 is a separate attachment that lists the specific 50% owners triggered by Schedule B questions 2a and 2b.
Related reading
- Does a Partnership Actually Issue a K-1? – Avoid this Mistake + FAQs
- How to Fill Out IRS Form 1065 – Schedule K-1 + FAQs
- How to Fill Out IRS Form 1065 – Schedule K-2 + FAQs
- How to Fill Out IRS Form 1065 – Schedule K-3 + FAQs
- How to Fill Out IRS Form 1065-X (w/Examples) + FAQs
- How to Fill Out IRS Form 8805 (w/Examples) + FAQs
- How to Fill Out IRS Form 8300 (w/Examples) + FAQs