When two LLC members become one, partnership tax rules shift

A partnership loses one member and gains a completely different federal tax identity, usually without anyone in the deal realizing it happened. When one owner buys out the last remaining partner in an LLC taxed as a partnership, the IRS doesn't see a business that simply got smaller. It sees a partnership that ended and a new federal tax reporting regime that started the very next day.

That distinction catches a lot of practitioners off guard, especially when a client insists, "Nothing really changed. We just bought out my partner." Something did change, and it shows up on the tax return, with the employer identification number (EIN) and even in how the remaining owner gets paid.

The buyout that quietly ends a partnership

Under Rev. Rul. 99-6, a multi-member LLC classified as a partnership becomes a single-member LLC the moment one member acquires every other ownership interest. The trigger isn't the purchase price. It's the shift in federal tax classification from partnership to disregarded entity. Here's the part clients rarely expect: the LLC itself doesn't terminate. An LLC is a legal entity created under state law, while a partnership is simply how the IRS classifies it for federal tax purposes.

The business can keep operating under the same state registration even though its partnership tax identity ends. One more wrinkle worth flagging for clients with more than two partners: if two or more members remain after a buyout, the entity still files as a partnership, and Rev. Rul. 99-6 never comes into play. That deal may instead trigger a basis adjustment under §743 if a §754 election is in effect, which is a very different conversation.

The clock starts the moment the partnership ends

Once the partnership terminates, a final short-year Form 1065, U.S. Return of Partnership Income, is generally required through the termination date. The remaining owner then reports business activity as a disregarded entity starting the following day, assuming no other election is made.

Under §6072, that short-year return is due the 15th day of the third month after the short tax year closes, which arrives faster than most people expect for a return built around a single, unplanned transaction. Form 7004, Application for Automatic Extension of Time to File Certain Business Income Tax, Information, and Other Returns, can buy extra time if the numbers aren't ready.

What happens to the EIN after the final return

Filing the final Form 1065 doesn't automatically shut down the partnership's EIN. Whether a new one is needed depends on the IRS's EIN rules for the resulting entity, not on the return itself. In practice, a disregarded single-member LLC will need its own EIN if it has employees or certain excise tax obligations. IRS Publication 1635, Understanding Your EIN, is worth keeping bookmarked for exactly this kind of question.

The remaining owner still isn't an employee

The remaining owner isn't an employee for federal tax purposes before or after the buyout. During the partnership's stub period, compensation is reported as guaranteed payments or a distributive share, not wages on Form W-2, Wage and Tax Statement. After the conversion, the owner generally takes draws rather than wages. Elective deferrals can't run through payroll withholding. Retirement contributions instead get calculated from net earnings from self-employment, a detail that trips up clients who still think in employee terms even after they take full control.

Plan the transaction before it closes

The theme running through all of this is timing. Once an ownership change makes an LLC a single-member entity, the tax consequences are already locked in. The better move is evaluating the short-year filing requirement, the EIN question and any reporting under §751 or §1060 before the deal closes, not after the final return is already overdue.

If a buyout is on the horizon for a client's LLC, walking through these questions early can turn a messy surprise into a clean transition.

To learn more about navigating the tax consequences when a multi-member LLC becomes a single-member LLC, watch NATP's Navigating from a Multi-Member LLC to a Single-Member LLC on-demand webinar.