How Your Best Customer is a Buyer’s Biggest Concern

There is a particular kind of frustration that belongs exclusively to business owners who have spent decades building something real and profitable, watched a major customer grow their spend year after year, and then been told by a parade of buyers that the business isn’t sellable.

That frustration is legitimate. And it points to one of the most underestimated dynamics in the lower middle market: customer concentration.

What Concentration Actually Tells You

When a single customer represents 30%, 40%, or 50%+ of a company’s revenue, buyers see risk. That should be intuitive. If that customer walks, the business changes overnight. No buyer wants to close a transaction and immediately face that scenario.

But here is what that same concentration tells anyone willing to look past the headline number: a major customer, often a large national or regional enterprise, made a deliberate decision to consolidate significant spend with this company. They did not stumble into that relationship. They stayed in it, year after year, and kept buying more.

Customer concentration exists, in most cases, because the company is doing something right. The concentrated customer has an appetite that the business earns, repeatedly. That is not a red flag dressed up as a compliment. It is a genuine signal of operational capability, reliability, and relationship quality that most buyers never stop long enough to appreciate.

The tragedy is that the market does not price it that way.

Two Transactions That Tell the Full Story

The Food Manufacturer Who Never Found His Number

We worked with the owner of a food manufacturer that distributed its products nationally. The company had been in business for decades. It was profitable, operationally sound, and had built a long-term relationship with a major national customer that had become its largest by a substantial margin, representing over 50% of annual revenue.

The reason for that concentration was straightforward…demand. The national customer’s appetite for the company’s products consistently outpaced the company’s capacity to produce them. The owner was not chasing this customer or dependent on them out of weakness. The customer simply wanted more than the company could supply.

By most measures, the company was a success story. Revenue was above $50 million, margins were strong, the customer base included over 100 accounts, and a major national buyer had been coming back for more than 20 years.

None of that mattered to most buyers.

Nine out of ten passed on concentration alone. The buyers who did engage applied discounts that pushed the valuation below what the owner was willing to accept. After an extended process, no transaction occurred at an acceptable price. The owner took the company off the market and went back to running it. Whether that was the right outcome is debatable. What is not debatable is that a legitimate, well-run business with a real earnings history failed to transact because the market could not get past a number.

The Service Company That Lost Its Customer Mid-Deal

The second situation is harder to tell. It is also more instructive.

We represented a California industrial service company with a single customer representing over 70% of revenue. The relationship was long-standing and there was no obvious reason to believe that would change.

Because of the concentration, almost every buyer we approached passed early. The buyer pool was thin from the start, and with so few interested parties, it was impossible to create any meaningful competitive tension in the process. We eventually received an offer that was acceptable to the owner from the one buyer who had gotten comfortable enough with the risk to move forward.

Then the customer left.

It happened during the diligence process. The business, almost overnight, contracted to a fraction of its former size. The transaction did not close. The company’s situation changed dramatically.

This is the scenario that every buyer citing concentration risk is afraid of. And in this case, they were right to be.

What These Two Cases Actually Mean

The temptation is to look at these situations and draw a clean conclusion. Concentration is bad. Avoid it completely or fix it before you go to market. That advice is not wrong. If you have time and the ability to diversify your customer base before a sale process, you should do it. The valuation improvement alone is usually worth the effort.

But that is not always realistic. Customer concentration in the lower middle market often is not the result of poor strategy. It is the result of one very good customer who found you, trusted you, and kept buying. You cannot always manufacture diversification on a timeline that aligns with your exit.

What you can do is go into a sale process with clear eyes.

Concentration will discount your valuation. In a best case scenario, buyers who do engage will apply a haircut to account for the perceived risk, and your offer will reflect it. Structural considerations like earnouts or clawback provisions could also enter the conversation, as buyers look for ways to share the downside risk with the seller. In a more common scenario, a significant portion of the buyer universe will pass before the first conversation goes anywhere meaningful.

That does not mean a transaction is impossible. It means the process needs to be run with a strategy built around the reality of your business, not around the hope that buyers will see past the number on their own. That requires positioning the concentration in context, being honest about the history and durability of the relationship, and targeting buyers who are either less risk averse by nature or who see the anchor customer as an asset rather than a liability.

The Harder Truth

The food manufacturer’s owner built a business that a major national company trusted for over two decades. The service company built a relationship strong enough to sustain the majority of a company’s revenue for years.

Both of those are real achievements. The M&A market largely did not reward them.

That is worth knowing before you decide to sell, not to discourage you, but to make sure you are not surprised when the process reveals a buyer universe that is smaller and more cautious than you expected. A good advisor will tell you this on the front end. The worst time to learn it is when you are three months into a process and most buyers have passed.

Customer concentration is manageable. It is not always fixable. And in many cases it is the byproduct of success rather than poor planning. But when it comes time to sell, the cost comes due regardless of how it was built.