What is vendor due diligence (VDD)?
A core M&A Advisory interview question — asked in analyst and associate interviews across IB, PE, and the Big 4.
THE SHORT ANSWER
Vendor due diligence is diligence commissioned by the SELLER (and its advisers) before going to market, producing independent reports (financial, commercial, legal, tax) that are then made available to bidders — usually under reliance/release arrangements. It's a proactive sell-side tool: it lets the seller control the narrative and identify and address issues before buyers find them, levels the playing field by giving all bidders the same baseline (important in an auction to keep momentum and competition), and accelerates the process by reducing duplicative buy-side work and management disruption. Bidders still do confirmatory/top-up diligence and don't rely on VDD blindly, but it shortens timelines and supports a cleaner, faster auction. The trade-offs: cost (borne by the seller), the need for the VDD to be genuinely robust and credible (a whitewash gets discounted and damages trust), and reliance/liability arrangements with the eventual buyer. It's standard in larger, competitive European sale processes.
WHAT INTERVIEWERS LISTEN FOR
- ✓Seller-commissioned independent DD reports given to bidders (under reliance)
- ✓Controls the narrative, surfaces issues early, levels the auction field
- ✓Speeds the process; reduces duplicate buy-side work and management disruption
- ✓Bidders still do confirmatory DD; cost borne by seller; must be credible
COMMON MISTAKES
- ✗Thinking VDD is buyer-commissioned
- ✗Assuming bidders rely on it without confirmatory DD
- ✗A whitewash VDD that loses credibility
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