What Is a Buy-Sell Agreement and Why Do Co-Owners Need One?

What Is a Buy-Sell Agreement and Why Do Co-Owners Need One?

A buy-sell agreement is a binding contract among the owners of a business, and often the business itself, that governs what happens to an ownership interest when a defined event occurs. It sets who may buy, who must sell, how the price is determined, and how the purchase gets paid for. It is sometimes called a business prenup, which understates it.

Here is the reason it matters. Without one, your next co-owner is chosen by someone else: a probate court dividing an estate, a divorce court dividing marital property, a bankruptcy trustee liquidating an interest, or a departing partner who sells to whoever will pay. You will still have a business partner. You just will not have picked them.

The Triggering Events a Real Buy-Sell Agreement Covers

Most agreements cover death. Fewer cover the events that actually happen more often.

A complete agreement addresses death, long-term disability, voluntary retirement, voluntary departure to do something else, involuntary termination including for cause, divorce, personal bankruptcy or a creditor attaching an interest, loss of a required professional license, and a deadlock among owners who cannot agree.

Divorce and disability deserve specific attention. Divorce can place a business interest in front of a family court, and an agreement that restricts transfers and gives the other owners a purchase right is what usually keeps an ex-spouse from becoming a shareholder. Disability is harder, because it requires defining disability, choosing who determines it, and setting a waiting period. Agreements that skip the definition tend to fail exactly when someone is too sick to negotiate.

Deadlock is the one nobody wants to write. Two 50 percent owners who cannot agree have no mechanism to break the tie unless the document provides one, and there are established options: a buyout right at a formula price, a forced-sale provision where one owner names a price and the other chooses whether to buy or sell at it, or binding third-party resolution.

How the Price Gets Set, and Where Buy-Sell Agreements Fail

Valuation is where most buy-sell agreements break, and it usually breaks in one of three ways.

A fixed price that goes stale. Owners agree on a number, write it in, and never revisit it. Ten years later the business is worth three times that figure and the agreement is a windfall for whichever side happens to be buying.

A formula that stops describing the business. A multiple of trailing revenue or earnings is simple and can work well for years, then stops working when the business changes shape. Add debt, change the revenue mix, or have one abnormal year, and the formula produces a number nobody would accept in an arm's length transaction.

An appraisal process with no process. "Fair market value as determined by an appraiser" sounds rigorous and is nearly useless without the details: who selects the appraiser, what standard of value applies, whether minority and marketability discounts are permitted, the timeline, who pays, and what happens if the parties get two appraisals that differ by 40 percent.

The workable middle ground is usually a defined formula with a stated review interval, plus an appraisal mechanism with named procedures as a backstop. What matters is that the method is specific enough that two people reading it under stress reach the same number.

One more point, because it is frequently misunderstood. A price set in a buy-sell agreement does not automatically control the value used for estate tax purposes. Specific requirements have to be met for an agreement's price to be respected for that purpose, including that it be binding during life as well as at death and that it reflect terms comparable to an arm's length arrangement. Valuation language drafted for a buyout and valuation language that will hold up for tax are not automatically the same thing, which is why this drafting belongs with an attorney and a CPA together.

Cross-Purchase, Entity Purchase, or Hybrid

The structure determines who writes the check, who owns any insurance, and what happens to tax basis.

	Cross-purchase	Entity purchase (redemption)	Hybrid
Who buys the interest	The remaining owners individually	The company itself	The company gets a right, owners get a backup right, or the reverse
Who owns the funding policies	Each owner on the others	The company on each owner	Varies by design
Number of policies with 4 owners	Up to 12	4	Depends
Basis effect for remaining owners	Generally increases their basis in what they buy	Generally does not give remaining owners the same basis increase	Depends on which right is exercised
Gets unwieldy when	There are many owners or wide age gaps	Corporate-level tax or state law issues arise	Rarely, which is why it is common

The basis difference is the item most often overlooked and matters most when the business is eventually sold. In a cross-purchase, an owner who buys a departing owner's interest generally takes basis in what they purchased, which reduces gain on a future sale. In a redemption, the company buys the interest, and the remaining owners generally do not get that same step in their own basis.

The counterweight is administrative. With four owners, a cross-purchase can require each owner to hold a policy on each of the others, which is twelve policies with twelve premiums and twelve renewal dates. Hybrid designs exist mostly to solve this, giving the entity a first right and the owners a backup, or the reverse.

There is no structure that is correct in general. The entity type, the number of owners, their ages and health, state law, and the expected exit all move the answer.

Funding: An Unfunded Agreement Is Just a Promise

An agreement that obligates a purchase without identifying the money is a document describing a problem.

Life insurance is the most common funding tool for the death trigger, because the money arrives at the moment the obligation does. Who owns the policy follows the structure. Disability buyout coverage exists as well and is more often skipped, even though disability is the more likely event.

A sinking fund works if it is actually funded, and competes with every other use of cash in a growing business.

Seller financing through a promissory note is common in practice and shifts the risk to the departing owner or their estate, who now hold a note from a business they no longer control. If you use it, specify the term, the interest rate or how it is set, the security, and what happens on default.

A bank facility can work, and it is worth confirming rather than assuming, because a lender's willingness to fund a buyout of a departing key person is not guaranteed at the moment you need it.

Most workable agreements combine two: insurance for death and disability, a note for a voluntary departure.

When to Review Your Buy-Sell Agreement

Put a standing review interval in the document itself, and treat these as triggers regardless of the interval: any change in ownership, a material change in value, taking on significant debt, a marriage or divorce among the owners, a new owner joining, a shift in entity type or tax election, or an approaching retirement.

A ten-year-old agreement referencing a valuation formula from a different business is not protection. It is a document that will be litigated.

Frequently Asked Questions

Do I need a buy-sell agreement if I have an operating agreement?

Often yes. Many operating agreements and bylaws contain transfer restrictions but no complete buy-sell mechanism, meaning they say an interest cannot be transferred freely without saying who buys it, at what price, or with what money. Have counsel read what you already have before drafting something new, because the provisions may live in either document.

How much does a buy-sell agreement cost?

It varies with the number of owners and the complexity of the valuation and funding design, and it is legal work rather than a form. The relevant comparison is not the drafting fee but the cost of a disputed buyout without one, which routinely involves litigation, competing appraisals, and a business operating under a cloud while it plays out.

What is the difference between a cross-purchase and an entity purchase?

In a cross-purchase, the remaining owners buy the departing owner's interest individually, which generally gives them basis in what they buy. In an entity purchase or redemption, the company buys the interest, which is administratively simpler but generally does not give the remaining owners that same basis increase. The trade-off is basis benefit against the number of policies and the paperwork.

Can a buy-sell agreement set the value for estate tax purposes?

Only if it meets specific requirements, including being binding during life as well as at death and reflecting terms comparable to an arm's length arrangement. Assuming a formula price will automatically bind the IRS is a common and expensive mistake. If estate tax valuation is part of the reason you are drafting the agreement, that has to be designed in deliberately with tax counsel.

A buy-sell agreement is drafted by an attorney, but the valuation method, the funding plan and the tax consequences are accounting and planning questions, and getting those wrong is what makes an agreement fail when it is used. Sam's List lists accountants and financial advisors who work with closely held businesses on exactly this, with real client reviews on every profile. Start there.

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About the author: Kimberly Green is the cofounder of Sam's List, where business owners and high earners find vetted CPAs, financial advisors, and fractional CFOs. She's met one-on-one with 400+ financial professionals and writes from the real data behind thousands of client-advisor matches. Ask her anything about finding an accountant - she's heard it all, including the questions people are afraid to ask.