How Much of Your Income Really Sits With One Customer?
Ask an owner-manager who their biggest customer is and the answer comes straight away. Ask what percentage of turnover that customer represents, and the certainty usually drops off a cliff.
Concentration hides in plain sight
On paper, a customer list can look spread out: twenty, thirty, forty names on the ledger. In practice, a handful of them can be carrying most of the weight, with the rest sitting around the edges as noise. Nobody sets out to build a business this way. It happens gradually, one good relationship at a time, until the business is quietly dependent on people who could, in theory, walk away on their own timetable.
What the numbers actually show
Working through a client's own numbers usually settles the question fast, not what the owner believes their spread of customers looks like, but what the figures say it actually is. It's common to find one or two customers responsible for well over half of everything coming in, sitting alongside a long tail of smaller accounts that make the overall picture look healthier than it is.
This isn't a story about one business. It's a pattern that shows up often enough, across different sectors, that it's now one of the first things I look for whenever I go through a business's numbers. It's a read, not an accusation: the business built the relationship because it was good business at the time. The question is whether anyone has stood back and looked at what it's since become.
Why this is a commercial-management question, not just a sale-readiness one
Customer concentration matters if you're ever selling. A buyer prices it in before they price almost anything else, because a business that depends on one relationship is a business the buyer doesn't fully control. But it matters just as much if you never sell. A customer that's become half the book is a single point of failure the business carries every week it trades, whether or not an exit is anywhere in the picture.
That's the same discipline that sits behind holding your margin once a job is won: not a once-a-year exercise, but an ongoing read of who and what the business actually depends on, done with real numbers rather than a gut feel.
Start with the question
You don't need a forensic project to start. Add up what each customer has actually paid you over the last year. Most owners are surprised, one way or the other, by what the total says. If the top one or two names account for more than you'd guess, that's worth knowing now, not the week someone makes you an offer.
If you want that read done properly on your own numbers, book a call.