The Seller Who Was His Best Customer

I was sitting in my office at a plumbing company in Central Texas when my bookkeeper walked in with a look on her face I hadn't seen before. Kris had been with the company seventeen years - essentially since day one. She knew every customer, every address, every job we'd ever run. She knew which water heaters we'd replaced, which slab leaks had turned into six-figure renovations, which commercial accounts called every spring like clockwork. We'd been doing forensic accounting for weeks. Revenue was down significantly from where it should have been for the time of year, and we couldn't figure out why. We pulled historical trends, looked at seasonality, mapped call volume against the prior year. Something was missing and we couldn't see it. She came in and said: "I think I know what's going on." She'd been going through our customer list - printed, sorted by annual dollar amount, each address treated as a separate customer. And as she worked through it, something started to surface. Address after address after address. Residential properties, commercial buildings, a portfolio she'd watched grow over seventeen years of service calls. She looked up and said: "Oh my god. These are all Chris." The seller, the guy who'd built this business from one truck to ten, who'd shaken hands and signed papers and walked out the door, had effectively been running a plumbing company to service his own real estate empire. Fifty-plus residential properties. Twenty-five to thirty commercial buildings. Two or three calls a week, steady, year after year. Never flagged as customer concentration because he never called them in himself. Other people did. Each address looked like a separate customer. Nobody had ever added them up. When he left, he tried using us for a while. Felt we charged too much. Which was ironic... he'd set those rates himself, back when he was effectively billing his own portfolio at cost. A million-plus dollars in annual revenue. Gone. Here's what I want searchers to understand: he didn't lie. Nobody asked. In M&A, sellers optimize for the best presentation of their business — that's not malice, that's incentive. The burden of asking the right questions falls entirely on the buyer. A customer concentration analysis should have caught this. One question — "Are you or any related parties current customers of this business?" — would have caught this. It didn't happen. Don't let that be your story.