Diligence Is Looking for One Number
A first-time acquirer treats diligence like a home inspection. Confirm the roof, check the wiring, tick the boxes, close. That approach costs real money, because diligence on a business is not confirming the seller's story. It is hunting for the one thing the story leaves out and deciding what that thing is worth.
The number you find in week four is the number you live with for the next 3 years. It pays to know where it usually hides.
Quality of earnings is most of the work
In middle market financial diligence, the quality of earnings analysis is the single largest workstream, roughly 30 percent of the total effort according to DealRoom. Working capital, tax, customer concentration, and controls divide up the rest. There is a reason the money and hours concentrate here.
A quality of earnings review walks reported EBITDA down to what actually recurs. The add-back that does not survive contact. The revenue booked a quarter early. The expense labeled one-time that has shown up as one-time in three straight years. None of this is fraud most of the time. It is a seller presenting his business the way anyone would present a house before an open door, and your job is to see it as a buyer who has to live there.
The stakes are not small. Reporting on Fall 2025 data, Middle Market Growth noted that material quality of earnings findings commonly reprice deals by 5 to 15 percent, and in the worst cases push past 30 percent or end the deal outright. The same reporting found that deals with a sell-side quality of earnings report closed at a median 7.4 times EBITDA against 7.0 for those without. The analysis moves the price in both directions. Which direction depends on who did it and how honestly.
The working capital peg is where money moves quietly
Almost every lower middle market deal includes a working capital peg, and it is the mechanic buyers understand last and pay for first.
Here is the plain version. The price assumes the business arrives with a normal amount of working capital, enough receivables and inventory to keep running the day after you own it. A target gets set from the company's own history. At close, the price adjusts up or down for the gap between that target and what is actually there. Simple enough, until you notice what a motivated seller can do in the weeks before closing. Collect the receivables early. Stretch the payables. Let inventory run thin. Every dollar pulled out that way is a dollar you quietly fund back in after the keys change hands, unless the peg was set with care and someone checked the trend rather than the snapshot.
This is not exotic. It is where six figures change owners without anyone raising their voice, and it is invisible to a buyer who thought diligence was about the income statement.
What diligence actually buys you
Not comfort. The point is a repriced deal, a renegotiated term, or a clean walk while walking is still cheap. And underneath that, a map for the year after close.
The connection to what comes next is direct. KPMG's 2025 integration survey found that projected synergies land at about 17 cents for every modeled dollar. Bain reported that only about 30 percent of strategic acquisitions met their own internal targets. Those are not integration failures that appeared out of nowhere after signing. They are diligence failures that took a year to surface. The gap between the model and the business is set during diligence, before anyone touches integration.
So do not send your team in to confirm. Send them in to find the number nobody wanted found, and give them the time and the mandate to keep looking until they do. A deal that survives real diligence is not a deal you got comfortable with. It is a deal you priced with your eyes open.