What technical due diligence costs, and what drives the price

Technical due diligence cost is one of the least transparent numbers in the deal business, so here are real ranges. Papermark’s due diligence cost guide puts specialized technology firms at 35,000 to 95,000 dollars per engagement and Big Four technology advisory at 50,000 to 150,000, and its worked example of a 12 million dollar SaaS acquisition budgets 22,000 for the technical workstream. That matches what we see in the European market: a focused read sits in the low tens of thousands, a full audit in the mid tens of thousands, and the six-figure quotes come from brand-name providers on large or multi-entity targets.

Put against the deal, the number is small. Technical diligence on a mid-market transaction is typically well under one percent of deal value, for the workstream most likely to find something that changes the price. It is also the line buyers most often try to shrink, so it is worth being precise about what the money buys.

What drives technical due diligence cost

Four variables move the quote more than anything else.

Scope is the first and biggest. A 3 to 4 day focused read and a 2 to 3 week full audit are different products at different prices; we described what each covers in how long technical due diligence takes. Deciding which question you need answered, before requesting proposals, is the single best way to control cost, and the full checklist shows what a complete scope contains.

Codebase size and entity count come next. One product, one repo, one team is the base case. Three acquisitions imperfectly merged, two legacy platforms and a rewrite in flight can double the effort, because each system needs its own read.

AI depth is the newest driver. Verifying AI claims properly, eval sets, production traffic, unit economics, takes senior people who build these systems themselves, and adds days. A target whose valuation rests on its AI should expect the AI assessment to be a third of the engagement rather than a paragraph.

Deadline pressure rounds it out. A ten-day window from kickoff to investment committee means senior reviewers working in parallel rather than a small team working in sequence. The findings are the same, the calendar is compressed, and the price goes up. Starting the clock a week earlier buys the same depth for less money.

Boutique or Big 4

The Big Four sell integration: technical findings folded into a broader financial and commercial package, one throat to choke, a brand the LP committee recognizes. That is worth real money on large transactions with many workstreams.

Specialist firms sell depth per euro. The people reading the code are the product, so ask the one question that matters for either option: who will be in the repos, and when did they last build something? A report assembled by analysts from a checklist and an interview reads very differently from one written by engineers who ship AI systems for a living, and on AI-heavy targets the difference shows up in the findings that change deals: eval practice, margin sensitivity, claims that do not survive contact with production data.

The most expensive diligence is the cheap one that missed

The cost conversation inverts the moment something is missed. A 20,000 dollar review that waves through a target with an unbudgeted rewrite, a data-rights problem, or a system only one person can operate has not saved 40,000 against the thorough option. It has cost whatever the miss costs: months of the value-creation plan spent on remediation nobody priced, a renegotiation that happens after close instead of before, or in the worst case a write-down.

We keep meeting the aftermath: an owner discovering in month three what a proper audit would have found in week two, at a price two orders of magnitude higher. Shrinking diligence to save money is a mistake we see repeated, and it is always the finding you did not pay to look for that gets you.

So the practical advice: scope the diligence to the question rather than to the smallest number in the proposals, and weight providers by who does the work. For a concrete reference point, our technical and AI audit runs from a focused multi-day read to a full 2 to 3 week engagement, priced by scope, with the risk register and remediation costs that turn the price discussion into an evidence discussion.