Five things due diligence always misses.

Introduction

Due diligence has a bias problem. It's very good at finding the things that are easy to measure — revenue, costs, margins, legal liabilities. It's much less good at finding the things that determine whether an acquisition actually creates value.

Here are five things we've seen missed repeatedly — and what to do about it.

01 — Customer concentration risk

Most financial due diligence looks at revenue by customer. What it often misses is the nature of those customer relationships — how loyal they actually are, how easily they could switch, and whether they're staying because of the product or because of a relationship with a person who might not survive the acquisition.

We've seen acquisitions where the top three customers represented 60% of revenue and had relationships exclusively with the founder. When the founder left post-acquisition, two of the three followed within eighteen months.

02 — The real competitive position

Vendor management presentations are optimistic by design. The competitive analysis in the data room shows the target in the best possible light. What it usually doesn't show is how customers actually think about the alternatives — whether they're actively evaluating competitors, whether a new entrant has changed the dynamics, whether the moat is as wide as it looks from inside.

The only way to get an honest picture of competitive position is to talk to customers and competitors directly. Most due diligence teams don't.

03 — Management depth below the leadership team

Acquirers spend a lot of time assessing the leadership team. They spend much less time understanding the layer below — the people who actually run the operations, manage the key customer relationships, and hold the institutional knowledge.

In most acquisitions, the leadership team is retained through earn-outs and incentive packages. The layer below has no such incentive to stay. We've seen acquisitions where the real operational capability walked out the door in the first six months because nobody had thought to ask whether those people wanted to be part of the new organization.

What to do

None of these gaps are inevitable. All of them can be addressed with the right commercial due diligence process — one that goes beyond the data room and involves direct conversations with customers, competitors, and the broader organization.

The question is whether you're willing to spend the time and money to do it properly before you sign, rather than discovering the issues afterwards.