How to Report a Partnership Interest Sale on Form 1065

To report a partnership interest sale on Form 1065, the partnership files Form 8308 as an attachment to the return when the partnership holds Section 751 property, issues two Schedule K-1s for the year of the sale (one closing out the departing partner, one opening for the buyer), and attaches a Section 743(b) basis-adjustment statement if a Section 754 election is in effect or a mandatory adjustment applies. Calendar-year partnerships file Form 1065 by March 15 of the following year, with a six-month extension available through Form 7004.¹ The partnership pays no income tax itself, so the whole point of these filings is to route the right numbers to the right people.

What to Gather Before Filing

Reporting starts with facts the partnership needs from both sides of the transfer. Collect the full legal names and Taxpayer Identification Numbers of the seller and buyer, the exact closing date, and the total consideration: cash paid, fair market value of any non-cash property, and the amount of partnership debt the buyer assumed from the seller.

Then identify whether the partnership holds Section 751 property. Unrealized receivables and inventory items fall into this category, and the gain traced to the selling partner from these assets is taxed at ordinary income rates rather than capital gains rates.² This classification decides whether Form 8308 is required.

Finally, calculate the selling partner’s adjusted basis at the time of sale. Start with their original investment, add their share of income allocations and later contributions, then subtract distributions, losses, and deductions. That figure sets up the seller’s gain or loss and drives the entries on their final K-1.

Federal law also requires the selling partner to notify the partnership in writing whenever the sale involves Section 751 property.³ The partnership’s Form 8308 clock doesn’t start until that notice arrives.

Filing Form 8308 with Form 1065

Any partnership holding Section 751 property at the time of a sale attaches Form 8308 to its Form 1065 for the tax year that includes the exchange.⁴ Electronic filers upload it as a digital attachment. Paper filers place it directly behind the main return.

Parts I through III identify the transferor, the transferee, and the basic terms of the exchange. Part IV breaks down the selling partner’s share of gain or loss attributable to Section 751 property, collectibles gain, and unrecaptured Section 1250 gain.

Starting with the November 2025 revision, the partnership no longer furnishes Part IV separately to the buyer and seller by January 31. The Part IV figures now flow to the selling partner through Schedule K-1, box 20, using codes AB, AC, and AD.⁵

The partnership still must furnish a copy of Form 8308 with Parts I through III completed to both the transferor and transferee by January 31 of the year following the calendar year of the exchange. If the partnership didn’t learn about the sale until later, the deadline is 30 days after receiving notice.⁴

Issuing Two Schedule K-1s for the Year of the Sale

The partnership issues two K-1s: one for the departing partner covering the period they held the interest, and one for the incoming partner covering the rest of the year. A few line items need particular attention.

Item J: Ownership Percentages

Item J shows each partner’s profit, loss, and capital percentages at the beginning and end of the year. For the seller, the beginning column shows their percentages at the start of the year and the ending column shows zero (or a reduced percentage for a partial sale). Check the “Sale” box to indicate the decrease came from a sale. For the buyer, the beginning column shows the percentages that existed immediately after admission.⁶

Item L: Capital Account

Item L tracks the capital account on the tax-basis method. The departing partner’s ending capital account typically drops to zero after their share of income, distributions, and the sale itself are accounted for. The new partner’s beginning capital account reflects the value of the interest acquired. Report capital contributed during the year, share of current-year net income or loss, withdrawals and distributions, and any other adjustments consistent with the rules for computing adjusted tax basis in a partnership interest.⁶ Total equity has to reconcile to the partnership’s books.

Box 20: Section 751 Information

Under the revised Form 8308 rules, the selling partner’s share of Section 751 gain or loss, collectibles gain, and unrecaptured Section 1250 gain is reported in box 20 using codes AB, AC, and AD.⁵ This replaces the old requirement to furnish Part IV of Form 8308 separately to the seller.

Allocating Income Between the Old and New Partner

When ownership changes mid-year, the partnership must split that year’s income, losses, deductions, and credits between the departing and incoming partners. Federal law gives two options.⁷

The interim closing of the books method treats the sale date as the end of a short tax period. Actual income earned through that date goes to the departing partner; everything after goes to the buyer. It’s more precise but takes more bookkeeping.

The proration method takes the full year’s income and divides it based on the number of days each person held the interest. Simpler, but it can distort results when a concentrated financial event falls in one part of the year. The chosen method feeds directly into the income figures reported on each K-1.

Schedule B Questions Triggered by the Sale

Form 1065’s Schedule B contains yes-or-no questions that ownership changes can flip. If the sale results in any partner owning 50% or more of the partnership’s profit, loss, or capital, including indirect ownership under the constructive ownership rules, answer questions 2a and 2b accordingly.⁸ Question 10(a) asks whether the partnership has a Section 754 election in effect, which ties directly to the basis-adjustment reporting for the new partner.

Reporting a Section 754 Basis Adjustment

When a Section 754 election is in effect, the partnership adjusts the basis of its assets to reflect what the new partner paid for their interest.⁹ The adjustment, calculated under Section 743(b), aligns the incoming partner’s share of inside basis with their purchase price. If the buyer paid more than the proportionate book value of the assets, the adjustment increases their depreciable basis; if less, it decreases it.¹⁰

When the Adjustment Is Mandatory

Even without a Section 754 election, the adjustment is mandatory if the partnership has a substantial built-in loss immediately after the transfer. That exists when the partnership’s total adjusted basis in its property exceeds the fair market value of that property by more than $250,000, or when the transferee partner would be allocated a loss exceeding $250,000 if all partnership assets were sold at fair market value right after the transfer.¹⁰

Making the Election

To make a Section 754 election for the year of the sale, the partnership files a written statement with the Form 1065 return for that taxable year. The statement includes the partnership’s name and address and a declaration that it elects to apply Sections 734(b) and 743(b). The return must be filed by its due date, including extensions.¹¹ Once made, the election stays in place for all future transfers and distributions until revoked.

The Required Attachment

Whether the adjustment is elective or mandatory, the partnership attaches a detailed statement to Form 1065 showing how the total Section 743(b) adjustment is allocated across categories of partnership property, such as buildings, equipment, and intangibles. Allocations follow the rules in Section 755, which generally distribute the adjustment based on the fair market value of the assets. Include the new partner’s name and TIN so the IRS can match the adjustment to the correct person. Without this statement, the new partner cannot claim their share of depreciation or amortization tied to the purchase price.

If the Seller Is a Foreign Person

A separate withholding regime under Section 1446(f) applies when the seller is foreign. The buyer withholds 10% of the total amount realized, meaning the full sale price including any partnership liabilities assumed, and remits it to the IRS using Form 8288 within 20 days of the transfer date.¹² The buyer also files Form 8288-A for the foreign seller. Exceptions apply, including a certification from the seller that they are not a foreign person, along with other certifications described in the regulations.¹³ The buyer cannot rely on a certification it knows to be incorrect.

The partnership gets pulled in if the buyer fails to withhold. It must then deduct and withhold the shortfall (plus interest) from future distributions to that buyer, reporting the backup withholding on Form 8288 with Form 8288-C attached.¹⁴

Replacing the Partnership Representative If They Left

If the departing partner was serving as the partnership representative, the partnership designates a replacement using Form 8979.¹⁵ Prior actions of the former representative remain valid, but a current designee must be in place going forward.

Penalties for Late or Incorrect Filings

The IRS imposes separate penalties for failing to file Form 8308 correctly and for failing to furnish copies to the buyer and seller on time. For returns due in 2026, the penalty per form or statement is $60 if corrected within 30 days, $130 if corrected by August 1, and $340 if never corrected or filed after August 1. Intentional disregard of the filing requirement raises the penalty to $680 per form or statement.¹⁶ Because the filing obligation and the furnishing obligation are separate, missing both deadlines produces double exposure.

Penalties can be waived if the partnership shows reasonable cause and that the failure wasn’t due to willful neglect.⁵

1
Internal Revenue Service. First Quarter Tax Calendar
2
Office of the Law Revision Counsel. 26 USC 751 – Unrealized Receivables and Inventory Items
3
Office of the Law Revision Counsel. 26 U.S. Code 6050K – Returns Relating to Exchanges of Certain Partnership Interests
4
Internal Revenue Service. Instructions for Form 8308 (11/2025)
5
Internal Revenue Service. Instructions for Form 8308
6
Internal Revenue Service. 2025 Partner’s Instructions for Schedule K-1 (Form 1065)
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Office of the Law Revision Counsel. 26 U.S. Code 706 – Taxable Years of Partner and Partnership
8
Internal Revenue Service. 2025 Instructions for Form 1065
9
Office of the Law Revision Counsel. 26 U.S. Code 754 – Manner of Electing Optional Adjustment to Basis of Partnership Property
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Office of the Law Revision Counsel. 26 U.S. Code 743 – Special Rules Where Section 754 Election or Substantial Built-In Loss
11
eCFR. 26 CFR 1.754-1 – Election to Adjust the Basis of Partnership Property
12
Internal Revenue Service. Instructions for Form 8288 – U.S. Withholding Tax Return for Certain Dispositions by Foreign Persons
13
eCFR. 26 CFR 1.1446(f)-2 – Withholding on the Transfer of a Non-Publicly Traded Partnership Interest
14
Internal Revenue Service. Partnership Withholding
15
Internal Revenue Service. Designate or Change a Partnership Representative
16
Internal Revenue Service. Information Return Penalties