Customer Concentration Risk: When One Customer Is Too Much of Your Business

Most founders don't think of their biggest customer as a risk. They think of them as the reason the business works. That's exactly why customer concentration risk is so easy to miss: it shows up looking like your best year.

What customer concentration means

Customer concentration is how much of your revenue depends on a small number of customers. If one account pays a large share of your bills, your business is concentrated, whether that account is a national retailer, a general contractor, a single distributor, or one hospital system.

Customer concentration risk is what that dependence exposes you to. If that customer cuts volume, renegotiates price, gets acquired, or just leaves, a big piece of your revenue goes with them, and usually faster than you can replace it.

How to measure your customer concentration

You don't need software for this. Pull last year's revenue by customer and run two numbers:

• Your top customer's share. Their revenue divided by your total revenue.
• Your top five customers' share. The same math for your five biggest accounts combined.

Then do it for the last three years. A single year can fool you. The trend tells you whether you're getting more dependent or less.

So what counts as high? There isn't one official line for private companies, but there's a useful reference point. Public companies in the U.S. have to disclose any customer that makes up 10% or more of their revenue, because regulators consider that big enough for investors to care about. Buyers and lenders tend to think the same way. If one customer is well past that mark, expect them to ask about it, and expect the answer to affect the number.

Why concentration lowers what your business is worth

A buyer pays for the revenue they believe will keep coming after you hand over the keys. Concentration makes that belief shakier, and shaky shows up in the price.

In practice that tends to look like a lower multiple, more of the price pushed into an earnout that only pays if the big customer stays, or a buyer who asks for the contract to be renewed before closing. Lenders look at it the same way when they size your line of credit. If you're planning a sale or a handoff someday, concentration belongs on the same list as the rest of your business exit strategy.

It's also a close cousin of key man risk. One is too much of the business riding on one person inside the company. The other is too much riding on one customer outside it. Buyers price both, and many founder-led companies have both at once, because the founder usually owns the big relationship personally.

What it looks like when the big one leaves

Tim Dyer runs Manifesto, an independent agency. Around 2015 and 2016 they landed Intel, roughly a $10 million contract, and went from under $1 million in revenue to almost $10 million nearly overnight. They were running projects in 23 countries and winning awards. "We thought we were indestructible," Tim told Ben.

Within six months, Intel cut a big share of its workforce and let a group of agencies go. In Tim's words: "Our biggest client that we had 80% of our revenue was tied up with was going to disappear overnight, or at least over the course of six months."

What came after is the useful part. The rebuild took longer than the rocket ride, and Tim describes it as building "an agency stronger, better, with more heart, with more drive, diversification," with people who believed in the work instead of the head count they'd added to keep up with one client.

Why concentration feels like success right up until it isn't

The uncomfortable thing about Tim's story is that the concentration came from a win. Landing a giant customer is the kind of thing every owner hopes for, and while it's working, it feels like proof you've arrived.

Tim calls that a false summit: the moment you hit the number and believe you're at the top, when really you're standing on a ridge with a long climb behind it. That belief is what keeps owners from fixing concentration while it's still cheap to fix, which is while the big customer is happy.

It shows up in how owners treat that customer, too. Ben once coached a founder who wanted "respect and goodwill" from his largest account. Ben kept asking one question, "What does that get you?", until the real goal came out: he didn't want to get put out to bid. That's a very different problem, and it has a very different fix. Respect is something you hope for. Not getting put out to bid is something you can plan for.

The question that breaks the fear spiral

The other way concentration hurts you is quieter. When most of your revenue sits with one customer, every rumor about that customer lands in your stomach. Owners start running worst-case scenarios at 2 a.m. and making decisions from that place.

Ben's answer is to swap the spiral for a probability. Instead of "what if everything falls apart," he'll ask a founder something like "What's the probability of all your customers earning 50% less? What about 25% less?" The fear doesn't go away, but it turns into a number you can plan around, and a plan is something you can actually act on.

Alex Gertsburg shared a story on the podcast that shows what the other side of that looks like. A friend called him with bad news: "My largest customer has let me know that maybe next year and the year after that I'm going to have a 40% reduction in what they're going to pay me." Alex said the words that came into his head were "What a blessing." He wasn't being glib. A warning like that, two years out, is the best possible version of this news. It's time you can use.

How to reduce customer concentration

The fix is to keep your best customer and make sure they stop being the only thing holding the business up. We'd work it in this order:

1. Run the numbers honestly. Top customer share and top five share, three years running. Put it in front of your leadership team so it stops being your private worry.
2. Name what you actually want from the big account. Use Ben's question: what does that get you? A longer contract, a price floor, a second buyer inside their company, a sole-source position. Each one is negotiable. "Goodwill" isn't.
3. Put a ceiling on new dependence. Decide the share you won't let any one customer pass, and check new work against it before you say yes. Growing that account is fine. Growing it without a ceiling is how you end up at 80%.
4. Build the second and third legs on purpose. Use the cash the big customer throws off to fund the sales effort, the second market, or the product line that diversifies you. Ben frames diversification as de-risking: spreading out is the safer position, even when it feels like you're stretching.
5. Get the relationship off one person. If the account lives in your phone, it leaves when you do. Put more of your people in front of more of their people, and write down what you know about how they buy.

That last step is where most owners get stuck, because it means stepping out of the relationship that made the company. It's also the step that matters most to a buyer. If you can see yourself in this and want help doing the work in the right order, talk with Ben about coaching. It's the work he does with founder-operators every week.

And if a big customer is squeezing you on price because they know how much you need them, read our guide on how to stop competing on price. Concentration and pricing power usually travel together.

Start while the big customer is still happy

Every one of these steps is easier while your largest customer is growing with you. Once they've sent the letter, you're rebuilding under pressure, the way Tim did. The best time to diversify is the year it feels least necessary, which, if you're honest, might be this one.