Venture Capital Due Diligence: The 83-Day Investor Process

Venture capital due diligence is the investigation a fund conducts between deciding a company is interesting and wiring money: verifying the team, market, product, traction, financials, and legal record, and deciding whether the price makes sense given the risks it finds. A widely cited survey of how VCs decide puts the average time from first look to close at 83 days.

That survey, of 885 institutional venture capitalists at 681 firms by Paul Gompers, Will Gornall, Steven Kaplan and Ilya Strebulaev ("How Do Venture Capitalists Make Decisions?", NBER working paper 2016, published in the Journal of Financial Economics in 2020), found that, alongside that 83-day average, the average firm spent 118 hours on due diligence and called 10 references. Those are averages across firms and stages, not a timetable. A $250K pre-seed check gets days of diligence; a $10M Series A gets weeks.

Definition: Due diligence is the structured review of a company's people, business, numbers, and documents that an investor performs before an investment, to confirm what the founders have claimed and to surface risks that change the decision or the terms.

This guide is written from the investor's seat: what the fund does, in what order, and what it concludes. If you're a founder preparing for a raise, the founder-side due diligence checklist tells you what investors will ask for, and the data room checklist covers how to organize it before the requests arrive. For the fund's financial workstream in more depth, see financial due diligence.

What venture capital due diligence is trying to answer

Diligence can look like a mountain of documents. Strip it back and most processes, however long, come down to four questions:

Is what they told us true? Revenue, customers, product, team backgrounds, cap table.
What are the two or three risks that would kill this company, and can we live with them?
Does the price make sense given those risks? Can this investment plausibly return a meaningful share of the fund?
Do we want to work with these people for ten years?

The same survey shows where investors put their weight: 95 percent of VC firms rated the management team an important factor, and 47 percent called it the most important one, ahead of business model, product, and market. Let that ordering shape the plan. An hour on references and founder conversations usually beats an hour rebuilding the financial model.

The six diligence workstreams

1. Team. Background verification, reference calls (on-list and off-list), and time with the founders in unstructured settings. Impressive isn't the question. The question is whether their specific history suggests they can do the specific hard thing this business needs.

2. Market. Bottom-up sizing from customer counts and price, competitive mapping, and a view on "why now." An investor who relies only on the founders' TAM slide hasn't really done market diligence; they've read a deck.

3. Product and technology. Demo, product roadmap, technical review by someone qualified, and for regulated sectors, the compliance path. At seed, this is often a few hours with a technical advisor; at Series A it may be a formal code and architecture review.

4. Customers and traction. Direct customer calls (typically three to eight at seed), cohort and retention data, pipeline review, and concentration analysis. We think customer calls are among the highest-signal hours in most early-stage processes.

5. Financials. Historical numbers, burn, runway, unit economics, and the reasonableness of the forecast. The same Gompers, Gornall, Kaplan and Strebulaev survey found that about 80 percent of VC firms forecast cash flows for their investments, while 31 percent of early-stage VCs said they do not, which reflects how little a pre-revenue model can tell you. The financial due diligence guide covers this workstream in detail.

6. Legal and corporate. Charter, cap table, prior financing documents, IP assignment, employment agreements, litigation, and regulatory matters. Cooley GO's sample VC due diligence request list organizes this into nine lettered sections: actions and minutes, charter documents, capital stock, legal and regulatory, intellectual property, management and employees and consultants, debt financing, other agreements, and a miscellaneous section that picks up financial statements and the business plan. Counsel runs most of this workstream; the investor typically reads the summary and acts on the red flags. Still, read the cap table yourself, and early. In our view it's the one document that records what already happened rather than what the founders hope (our take on reading the cap table first).

A diligence request list, scaled by stage

Investors adapt the request list to the check size. An illustrative version:

Pre-seed and seed (days to two weeks) - Deck, product demo, and a short data pack (revenue, users, retention, burn). - Cap table and all prior SAFEs, notes, and option grants. - Certificate of incorporation, bylaws, and board consents. - IP assignment agreements for all founders and early employees. - Founder references: three to five each, at least two off-list. - Customer conversations: three to five.

Series A (three to eight weeks) - Everything above, plus monthly financials, a bottom-up model, and cohort data. - Material customer and vendor contracts. - Employment agreements, option plan, 409A valuation. - Litigation, regulatory correspondence, and insurance. - Technical review and a security overview. - Customer calls: eight or more, including churned customers.

The NVCA model legal documents define what the eventual financing paperwork will look like, so legal diligence at Series A is partly about confirming the company's existing documents can be brought into that standard without surprises.

Reference calls: practices investors often use

In our view, reference calls decide more early-stage deals than models do. Practices many experienced investors land on:

Go off-list. Founder-provided references are useful but curated. Former colleagues, former investors, and former customers found independently often tell you more. Our founder-side guide to how VCs run founder reference checks shows the same calls from the other side of the table.
Ask for stories, not ratings. "Tell me about a time this person had to change course" beats "how would you rate them?"
Listen for hesitation. What a reference does not say, and how long they take to say it, often matters more than the words.
Ask the closing question. "Would you invest your own money?" or "Would you work for them again?"
Calibrate. Ten calls with the same question let you compare answers. One glowing call on its own means little.

Investors also back-channel with other funds that saw the deal. A pass from another fund is data, not a verdict.

Timeline: what an 83-day average looks like

An illustrative seed process:

Week 1: first meeting, internal discussion, decision to proceed. Initial data request.
Weeks 2 to 3: product demo, customer calls, founder references, market work. Partner meeting.
Week 4: term sheet negotiated and signed. See term sheets for the investor's view of that document.
Weeks 5 to 8: confirmatory legal diligence by counsel, remaining references, investment committee approval, documents drafted and signed.
Weeks 8 to 12: closing and wire, often delayed by the company's own paperwork.

"In a hot round, there's no time for diligence"

Hot deals compress all of this to days, especially at pre-seed, where Carta's State of Pre-Seed report for Q2 2026 (published August 2026) recorded an average instrument size of $276K, the highest in more than four years of its data and up 27 percent year over year, with US startups raising $3.19B across more than 11,500 pre-seed instruments against 14,825 instruments a year earlier: similar dollars, fewer companies. Bigger checks chasing fewer companies means real competition, and a fund that insists on 83 days may simply lose the deal. We've argued ourselves that extended diligence became a liability for angel groups in a fast market.

But.

Speed and skipping aren't the same thing. The minimum (references, customer calls, cap table, IP) fits in a week if you start on day one. Compressed processes are where errors tend to happen, and if a fund can't do even that much, we'd let the deal go. Some investors accept that risk in competitive rounds; we'd rather miss a deal than wire money on a story nobody checked.

What kills deals in venture capital due diligence

Deals die in diligence for strikingly similar reasons across funds:

Numbers that do not reconcile. Revenue on the deck that does not match the bank statements or invoices.
Cap table problems. Unassigned IP, a departed co-founder with unvested equity, or stacked SAFEs whose conversion the founders have not modeled. The cap table guide shows how investors read one.
Customer calls that contradict the pitch. "It's a nice-to-have" from a customer described as a champion.
Reference hesitation. Repeated pauses on questions about integrity or how the founder treats people.
Concentration. Two customers as 60 percent of revenue, or one channel as all of growth.
Price. The company is real but the valuation requires an outcome the market has never produced in that category.

"Kill" is often the wrong word, though. Many findings lead to renegotiation: a lower price, a larger option pool, a milestone-based tranche, or a specific closing condition such as an IP assignment being signed.

Angels and emerging managers face the same questions with less time. Three habits transfer well from institutional practice: talking to customers, reading the cap table and prior documents yourself, and making at least two off-list reference calls. Much of the rest is learned by running real processes with somebody checking your work. Diligence on live companies is the spine of 1752vc's Venture Fellow program, eight weeks of live virtual sessions in which Fellows take real pitch materials apart and then have to say what they found and what they would do about it. The program is aimed at professionals moving into investing and founders who want to understand how investors decide, and applications are reviewed on a rolling basis.

The bottom line

Good diligence is less about volume than aim. Find the two or three risks that could sink the company, test them with people who have no reason to flatter the founders, and let the answers move the price or the decision. That's our approach; funds with different stages and check sizes will weigh it differently.

The deck is the founder's argument.

Diligence is the cross-examination.

Key takeaways

Venture capital due diligence can be framed as four questions: is the story true, what risks could kill the company, does the price make sense, and do we want to work with these founders.
The Gompers, Gornall, Kaplan and Strebulaev survey of 885 VCs at 681 firms found the average deal took 83 days to close, with 118 hours of diligence and 10 reference calls, and 95 percent of firms rating the team an important factor.
Six common workstreams are team, market, product, customers and traction, financials, and legal, scaled by stage and check size.
Off-list references and direct customer calls are often the highest-signal hours in an early-stage process.
Deals often die on numbers that do not reconcile, cap table and IP problems, contradicting customer calls, reference hesitation, concentration, and price, and many findings lead to renegotiation rather than a pass.

Frequently asked questions

What is due diligence in venture capital?

It is the investigation a fund performs after deciding a company is interesting and before investing: verifying the team, market, product, customers, financials, and legal record, and deciding whether the price is justified by the risks found. Counsel handles most legal diligence; the investment team handles the rest.

How long does VC due diligence take?

In the Gompers, Gornall, Kaplan and Strebulaev survey of 885 institutional VCs at 681 firms, the average deal took 83 days to close and the average firm spent 118 hours on due diligence. That is an average, not a norm: pre-seed checks can close in days, while a Series A commonly takes three to eight weeks of active diligence plus closing time.

What do VCs look for in due diligence?

Whether the founders' claims hold up, whether the team can execute the specific plan, whether customers actually value the product, whether the numbers reconcile, whether the cap table and IP are clean, and whether the valuation leaves room for a fund-returning outcome. In the Gompers, Gornall, Kaplan and Strebulaev survey, 95 percent of firms rated the management team an important factor and 47 percent called it the most important.

What documents do VCs ask for in due diligence?

Cooley GO's sample request list has nine sections: actions and minutes, charter documents, capital stock (including shareholder and optionee lists with issuance dates and prices), legal and regulatory, intellectual property, management and employees, debt financing including lease financing, other agreements, and a miscellaneous section covering audited and unaudited financial statements and the business plan. Seed-stage requests are shorter; Series A requests are close to the full list.

What are red flags in startup due diligence?

Revenue that does not match bank records, unassigned IP or a departed co-founder with unresolved equity, customer calls that contradict the pitch, references that hesitate on character questions, heavy customer concentration, and a valuation that requires an unprecedented outcome. Some of these end the deal; others change the price or add closing conditions.

Sources

Disclaimer: This guide is for general education only and is not legal, tax or investment advice. Laws, market data and program terms change, so it may not reflect the latest developments or fit your situation. Treat it as a starting point, not a source of truth, and talk to a qualified lawyer, accountant or financial adviser before you make decisions.