What Is Due Diligence in Startup Investing?
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Due diligence is the investigation an investor runs on a startup before committing money. The founders have made claims in a pitch: the team is strong, the market is large, customers are growing, the company owns its technology. Diligence is the process of checking those claims against evidence, then deciding whether the investment still makes sense and what to put in the legal documents to protect against what was found.
It happens in every institutional round, but its depth varies a lot. A friend writing a small check may ask a few questions over coffee. A lead investor in a priced round sends a lawyer through the company's records. This article describes common US practice, in general terms, and isn't legal advice.
What Investors Actually Check
Most diligence falls into five buckets. Investors weigh them differently, but all five usually get at least a look.
1. The team. This is the bucket that matters most to investors. In a survey of 885 institutional venture capitalists, the authors of How Do Venture Capitalists Make Decisions? (NBER Working Paper 22587, September 2016) report that VCs see the management team as more important than business characteristics such as product or technology. NBER's own summary of the study adds that over 55 percent of respondents considered the team the most important factor in a company's success or failure. So expect founder background checks, conversations with former colleagues, and questions about how the founders work together and handle conflict.
2. The market. Investors test whether the opportunity is big enough to return a fund. They look at the market's size and growth, the competition, and why now is the right time. Frameworks like TAM, SAM and SOM are the usual starting point, and a bottom-up estimate carries more weight than a number copied from an analyst report.
3. The product and technology. For software companies this can mean a review of the architecture, security practices, dependence on open-source or third-party components, and how much of the product is actually built versus promised. Some investors bring in a technical advisor for this step.
4. Traction and financials. Here investors check that revenue, retention and growth are real. They ask for monthly financials, a breakdown of customers, cohort data, and how the company has spent money so far. Metrics such as burn rate and runway get close attention, because they show how long the new money will last. Customer calls are common: an investor may phone a handful of customers to confirm what the pitch deck says.
5. Legal and corporate records. This is where deals most often get delayed. A law firm acting for the investor reviews the company's paperwork. Osler, a Canadian law firm, advises founders that investors will look at the corporate books (board composition, officers, shareholdings, past share transfers), the agreements that protect confidential information and intellectual property, the contracts with employees, consultants, customers and suppliers, and the cap table, which it calls one of the two documents investors look at first (the other is the business plan).
The Legal Checklist in More Detail
Because legal diligence is the most mechanical part, it's also the most preparable. Typical items include:
- Cap table and securities. Every share, option, warrant, SAFE and convertible note the company has issued, matched against board approvals. The cap table should tie out to the legal records, not live only in a spreadsheet. The employee option pool and any founder vesting also get reviewed.
- IP assignment. Everyone who built the product, founders included, should have signed an agreement assigning their work to the company. If a founder wrote code before the company was incorporated and never transferred it, the company may not own its core asset.
- Contracts. Customer and vendor agreements, especially anything with unusual exclusivity, change-of-control or termination terms.
- Corporate records. Certificate of incorporation, bylaws, board and stockholder consents, and minutes. Gaps here are common and usually fixable, but the fix takes time.
- Employment and compliance. Offer letters, contractor classification, and any pending disputes or regulatory issues.
Cooley GO, the startup resource of a law firm that handles a large volume of venture financings, publishes a sample VC due diligence request list described as a way to "understand what VCs will look for before they'll close your financing." It's worth reading before you raise, since the best time to find a missing assignment agreement is before an investor does.
Where Diligence Sits in the Deal
Many founders assume diligence happens before the term sheet. In practice it comes in two layers.
Light diligence comes first. Before issuing a term sheet, an investor has usually met the team, studied the deck and the metrics, and made a few reference calls. The VC survey above gives a sense of the filter: the authors report that roughly one in four opportunities lead to a meeting with management, one-third of those are reviewed at a partners meeting, and about half of those proceed to the due diligence stage. For the full funnel, see the readable copy of the paper.
Confirmatory diligence follows the term sheet. Once a term sheet is signed, the investor and its counsel go deep. Maret Delf of Amplify Partners writes that there's typically about four weeks between signing a term sheet and the initial closing, that the company works with its counsel to populate a data room with the documents investors expect to review, and that investor counsel will "likely ask for any issues that they uncover to be fixed before closing."
That's why a term sheet isn't a guarantee of money. Term sheets are generally non-binding on the main economic terms, and the investor can renegotiate or walk away if diligence turns up something serious. Signing the term sheet is a strong signal, but the deal isn't done until the closing documents are signed and funds arrive.
The Data Room
A data room is a secure online folder where the company stores everything the investor needs to review, organized by topic: corporate, financial, customers, product, IP, employees, contracts. Investors and their lawyers get access and work through it, often leaving written questions that the company answers.
Practical habits that make a data room work:
- Organize folders to mirror a standard request list, so reviewers don't have to ask where things are.
- Keep one version of each document, with clear names and dates.
- Open it to investor counsel early, rather than after the last item is gathered.
- Track who has access, and remove access when a deal ends.
- Log each question and answer, so the story stays consistent across reviewers.
How Depth Differs by Stage
Diligence scales with check size and with how hard the investment is to reverse.
| Stage | Typical depth | Main focus |
|---|---|---|
| Angel or pre-seed | Light. Calls, references, a read of the deck | Team and idea. There's little data to verify |
| Seed | Moderate. Founder references, some customer calls, basic legal review | Team, early traction, clean cap table, IP ownership |
| Series A | Heavy. Full financial review, customer calls, formal legal diligence | Repeatable growth, unit economics, legal cleanliness |
| Series B and later | Deepest. Detailed financial and commercial analysis, often outside advisors | Scale, retention, forecasts, contract exposure |
The table is a general pattern, not a rule. The Cooley and Amplify materials above are aimed at institutional rounds, while very early checks from an angel investor often depend more on trust and a quick read of the founders. One investor-side data point on effort: in the VC survey, the authors report that the average firm spends 118 hours on due diligence per investment and calls ten references (see the readable copy). Earlier-stage deals tend to get fewer hours simply because there's less to check.
A lead investor usually carries most of the diligence work in a round, and other participants often lean on its findings instead of repeating everything. If you're curious how seed rounds are typically structured, see the seed round entry, and for later rounds see Series A, B and C funding.
Common Red Flags
These are problems that commonly slow or sink a deal, in the general experience of startup lawyers and investors:
- Missing IP assignments. Work done by founders or contractors that was never assigned to the company.
- Cap table errors. Share counts that don't match the legal records, promised equity that was never papered, or unclear ownership of past SAFEs and notes.
- Metrics that don't reconcile. Revenue in the deck that doesn't match bank statements or the financial model.
- Unexplained gaps in the story. A founder's work history that doesn't match the pitch, or departures that nobody wants to discuss.
- Undisclosed liabilities. Pending disputes, tax issues, or customer contracts with surprise obligations.
- Messy corporate records. Missing board approvals or consents for share issuances.
- Evasive behavior. Slow, partial or defensive answers. Investors read how founders respond to hard questions as a signal in itself.
Most of these can be repaired if they're found and disclosed early. What damages trust is an investor discovering a problem the founder knew about and didn't mention.
How Founders Can Prepare
- Run a self-audit using a public checklist such as Cooley GO's, before you start raising.
- Reconcile the cap table to the legal records, and fix any gaps.
- Get IP assignment agreements signed by every founder, employee and contractor.
- Prepare monthly financials and a clean metrics pack.
- Build the data room before the term sheet, so the four-week window isn't spent gathering paper.
- Answer questions fully and quickly. Speed signals competence.
Key Facts
- The NBER study of 885 institutional VCs found they see the management team as more important than product or technology (NBER).
- Over 55 percent of respondents in that survey named the team the most important factor in success or failure (NBER digest).
- The average VC firm in the survey reports 118 hours of due diligence per deal and calls ten references (paper copy).
- There's typically about four weeks from signing a term sheet to the initial closing, during which investor counsel reviews the data room (Amplify Partners).
- Investors commonly review corporate books, IP and confidentiality agreements, contracts and the cap table (Osler).
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