Add-on diligence is broken at the national firms

Programmatic add-on acquisition is the dominant value-creation strategy in lower-middle-market private equity, and the diligence market has not caught up to it. A platform built to buy three to six small companies a year runs into a structural problem the first time it tries to diligence a $3M-EBITDA tuck-in: the diligence product on offer was designed for a different kind of deal.

The economics do not work, and everyone knows it

A national firm's full quality-of-earnings engagement is built for a $30M platform acquisition. It takes five or six weeks, runs through several layers of review, and carries a fee to match. Pointing that machine at a $3M tuck-in is absurd on its face. The fee is disproportionate, the timeline blows past the deal's natural close, and the work product is heavier than the decision requires.

So platforms do one of two things, and both are bad. Some skip diligence on the small deals entirely, treating them as too small to matter, until one of them turns out to have a customer-concentration problem or a working-capital hole that a two-week look would have caught. Others try to run the heavy process anyway and watch their add-on cadence grind to a halt because diligence has become the bottleneck.

The answer is a purpose-built product

The fix is not a cheaper version of the big engagement. It is a different engagement, designed from the start for the add-on context: senior-led so judgment is not lost, templated so the repeatable parts move fast, and scoped to the questions that actually decide a tuck-in. Adjusted EBITDA and add-back quality. Working capital. Customer concentration. The handful of things that, on a deal this size, are the deal.

Done right, that work fits in two to three weeks and carries a fee proportional to the target. It is not a corner cut. It is the recognition that a $3M add-on and a $30M platform are different decisions that deserve differently shaped diligence.

Why a retainer beats a queue

The other thing add-on-heavy platforms need is capacity they can count on. Deal timing is not something a buyer controls; the seller's banker sets the clock, and a hot add-on can go from indication to signed in weeks. A platform that has to find a diligence provider, scope a new engagement, and wait in someone else's queue every time loses deals to that delay.

A platform retainer solves this by reserving capacity in advance. The provider knows the platform, knows the thesis, knows the integration playbook, and holds bandwidth for the pipeline. Each new add-on starts from a running start instead of a standing one. Over a year of deals, that difference compounds, in speed, in consistency, and in the quality of the judgment applied, because the same senior people see every deal in the program.

The national firms are not built for this, and the local CPA firm has never seen a roll-up. The work belongs with a senior team that does add-ons on purpose.

If your platform is running an add-on program and diligence has become the bottleneck, let's talk about a retainer.