Due Diligence

Anyone buying a used car checks under the hood first. You want to know whether the car is worth the price and whether any defects have been hidden. That's exactly what happens when one company wants to buy another, or when an investor takes a stake in a young company. This systematic review before the deal is closed is called due diligence. The term literally means something like "the diligence that is owed." The idea is: you've done everything reasonably possible to form a realistic picture.

What's at stake when nobody checks

Company acquisitions often involve sums in the hundreds of millions. The seller knows their company inside out, while the buyer barely knows it at all. This imbalance of knowledge is the core problem. Due diligence is meant to narrow that gap before anything is signed.

If the buyer finds problems, that usually doesn't blow up the whole deal right away. More often, the price drops, or the seller has to stand behind certain risks. Such commitments are called warranties. Sometimes part of the purchase price is also only paid out later, once it becomes clear that everything checks out.

There's also a legal side to this. Anyone managing other people's money, such as a fund or a bank, must be able to prove they carried out a careful review. If that doesn't happen and things go wrong, liability and trouble with regulators can follow. Due diligence is therefore not just smart business practice, but often a legal obligation.

Data rooms, checklists, and specialist teams

The process is remarkably standardized. The seller places thousands of documents in a secure online area known as a data room. The buyer sends over lists of questions, and the answers are added there. Everything is logged, so that later on nobody can claim they weren't aware of something.

Different specialist teams examine different areas. Financial due diligence looks at revenue, profits, and debts. Legal due diligence examines contracts, litigation, and ownership rights. Depending on the case, this is joined by reviews of tax, HR, environmental issues, and technology. At the end stands a report that lists and assesses the risks found.

At technology companies, the technical review is often the most important part today. Who really owns the source code? Were third-party software components properly licensed? For AI companies, there's an additional sensitive question: where did the training data used to teach the model actually come from? Unresolved rights to this data can significantly reduce a company's value.

Where the term shows up in the news

When an acquisition is announced, it's usually noted that the closing still depends on the review. Months often pass between the announcement and the closing. If a deal falls apart during this phase, reports frequently say that due diligence uncovered unexpected risks. A well-known example is Elon Musk's acquisition of Twitter, during which he argued for weeks over the number of fake accounts.

The term is also used outside of company acquisitions. Banks conduct due diligence on new customers to prevent money laundering. Large corporations check their suppliers for child labor and environmental violations. In Germany, the Supply Chain Act specifically requires such reviews. The common thread is always the same: look before you buy, rather than accept liability after.

A common misconception is that due diligence is the same as an audit. An audit confirms that a set of financial statements was prepared correctly, and it looks backward. Due diligence, by contrast, looks forward: what will this company be worth in the future, and what risks am I buying along with it? So it doesn't provide a stamp of approval, but rather a basis for making a decision.