Stay Bonuses: 6 Rules to Keep Key People After You Buy a Company

In September 2017 Brian Acton, co-founder of WhatsApp, walked out of Facebook three years after it bought WhatsApp for $19 billion. According to Forbes, Acton left roughly $850 million in unvested stock on the table. A few months later co-founder Jan Koum left too, and in September 2018 the founders of Instagram, bought by Facebook in 2012, followed them out.

These were not people short of money. That is the point. If $850 million cannot keep a key person in the building, a retention bonus alone will not keep yours. It can still buy you the twelve or eighteen months you need, as long as you design it as part of the deal and not as an afterthought the week before closing.

The research says the risk is real. A 2019 MIT Sloan study by Daniel Kim, covering about 350,000 employees in 4,000 startup acquisitions, found that 33% of acquired workers left within a year, against 12% of comparable regular hires. When you buy a company, you are buying a team that did not choose you. Here are six rules I would apply before signing.

Why key people leave after a deal

Nobody asked them. The seller negotiated in private, the announcement arrived on a Monday, and overnight the people who actually run the customers, the machines and the books have a new owner they have never met. Kim's research points to exactly this: acquired employees lose agency, and the people who joined a small, fast company for its freedom often dislike the systems of a bigger one.

Add the obvious practical worry, "will my job survive the integration?", and the best people, the ones with the most options, start answering recruiters' calls first. The employees most likely to leave are precisely the ones you paid for.

Rule 1: Name the people before you name the price

During due diligence, make a short list of the people without whom the business you are buying is worth less. Not the org chart; the dependencies. Who holds the three biggest customer relationships? Who is the only person who knows how to run the production line, the ERP or the service bay? Whose license or certification does the company operate under?

In most small and mid-sized companies the list has three to eight names. If the value of the deal depends on a person, that person belongs in the deal documents, not in a post-closing to-do list. Ask the seller to help build the list, and watch how they react: a seller who cannot name their key people, or will not, is telling you something about the business. I covered the wider version of this in the due diligence red flags that should slow a deal down.

Rule 2: Size the bonus to the risk, not to the title

The ranges M&A advisers commonly cite run from about 25% to 50% of base salary for senior leaders and 10% to 25% for critical individual contributors. Use them as a sanity check, not a formula.

The better question is what it would cost if this person left in month four. Count the recruiting fee, the months without a replacement, the customers that might follow them and the knowledge that walks out the door. A stay bonus is cheap insurance when it costs a fraction of the loss it prevents, and wasted money when it goes to someone who was never going to leave.

• Concentrate the budget on the short list from Rule 1. Spreading small amounts across everyone buys gratitude, not retention.
• Be ready to treat people differently. Fair is not the same as equal, but expect the amounts to leak, and be able to explain them.
• Remember the money is a real cost of the deal. Put it in your model before you agree the price.

Rule 3: Pay it in stages tied to your integration calendar

A single payment at the end of the period creates the strongest pull, because nothing has been paid yet. It also creates a cliff: the day after payment is the most likely day to resign. Installments soften that cliff but weaken the pull.

Match the payment dates to the moments you cannot afford to lose the person, not to round numbers on a calendar. If the hardest part of the integration is migrating systems in month nine and transferring the key customer contracts by month twelve, pay a third at six months, a third at twelve and the last third at eighteen. The final payment should land after the work that depends on them is done.

Write down two cases clearly. If the person resigns, unpaid tranches are forfeited. If you dismiss them without cause or eliminate their role, the bonus is paid in full. Without that second clause, the bonus reads like a trap, and good people refuse traps. This is the same logic I described in designing incentives that make people behave like owners: pay for the behavior you need, on the timeline you need it.

Rule 4: Decide in the LOI who pays

Retention money can come from the buyer, from the seller out of the sale proceeds, or from both. Negotiate it early, ideally in the letter of intent, because the answer changes the economics and the incentives.

A seller who funds part of the stay bonus is telling you they believe their team will stay; a seller who refuses is telling you something too. Seller-funded bonuses also turn the outgoing owner into an ally of the retention plan, which matters, because the team trusts the seller more than it trusts you in the first months.

Whoever pays, model it honestly. A buyer-funded retention pool is a real cost of owning the business for the next eighteen months. It is not one of the "one-off" items a seller can add back to EBITDA, a distinction I explained in how to test a seller's add-backs.

Rule 5: Money buys presence, conversations buy commitment

The WhatsApp and Instagram stories show the limit of any financial arrangement. A bonus keeps a person on the payroll; only a clear role, real decision rights and a leader they trust keep them engaged. An unhappy expert who stays only for the next payment can do more damage than one who leaves.

So talk to each person on the short list within the first two days after the announcement, in person, before the rumors do the talking. Tell them what will not change, what will, and what you need from them. Ask them what they need from you. Then deliver on the first promise quickly, even a small one, because the first broken promise is what starts the job search.

Give them something money does not: a role in shaping the integration. People resist changes imposed on them and defend the ones they designed. This is the heart of the first 100 days after you buy a company.

Rule 6: Put it in writing, and check the local rules

A promise made in a hallway is a dispute waiting to happen. Each stay bonus deserves a short written agreement that states the amount, the dates, the conditions and what happens on resignation, dismissal, death or a change of role.

Keep the conditions simple and within the person's control: still employed and performing their duties on the date. Tying payment to targets they cannot influence turns a retention tool into a lottery ticket.

Check the local law before you add restrictions. What you can enforce after someone leaves varies by country and by state. In Spain, for example, a post-employment non-compete must be paid for and is limited by Article 21 of the Workers' Statute to two years for technical staff and six months for others. In the United States the rules differ from state to state. Non-solicitation and confidentiality clauses are usually easier to defend than a broad ban on competing, and the bonus is normally taxed as ordinary employment income, so agree whether amounts are gross or net.

Key Takeaways

• About a third of acquired employees leave within a year, against 12% of comparable new hires, according to MIT Sloan research.
• List the three to eight people the deal's value depends on during due diligence, not after closing.
• Size each bonus to the cost of losing that person, using the 25% to 50% of salary range for senior leaders only as a check.
• Pay in tranches tied to your integration milestones, forfeited on resignation and paid in full on dismissal without cause.
• Decide in the LOI whether the buyer, the seller or both fund the pool, and model it as a real cost.
• A bonus buys presence. Role clarity, decision rights and an early, honest conversation buy commitment.
• Paper every bonus and check local rules on non-competes and taxes before you promise anything.

Frequently Asked Questions

How much is a typical retention bonus in an acquisition?

Advisers commonly cite 25% to 50% of base salary for senior leaders and 10% to 25% for critical individual contributors, paid over 6 to 36 months. The right amount depends on what it would cost you if that specific person left during the integration.

Who pays for retention bonuses, the buyer or the seller?

Either, or both. Buyers usually fund them as a cost of the integration, but sellers often contribute from the sale proceeds, which signals confidence in the team. Agree the split in the letter of intent so it is reflected in the price.

How long does a retention period usually last after an acquisition?

Most retention periods run 12 to 24 months after closing. Set the length by your integration plan: the last payment should come after the systems, customers or knowledge that depend on the person have been transferred.

What happens to a retention bonus if the employee is laid off?

That depends on the written agreement, which is why you need one. A fair agreement pays the bonus in full if the company dismisses the person without cause or eliminates the role, and forfeits unpaid installments if the person resigns.

Do retention bonuses actually work?

They work for keeping people through a defined window, but not for keeping them committed. Research on acquisitions shows departures are driven by loss of autonomy and cultural mismatch, so pair any bonus with a clear role, decision rights and a leader the person trusts.

Before You Sign

Write the short list of key people on one page, next to the cost of losing each one and the date you could finally afford to. If that page is empty, you have not finished your due diligence. To see how we think about buying and building companies over generations, explore the Manzanos Enterprises group.