Startup due diligence: what investors check, seed to Series A

A pre-seed deck gets about four minutes of a VC’s attention, on DocSend’s data. Checking that it’s true takes a lot longer. In a survey of 885 venture capitalists, the average deal took 83 days to close, with 118 hours of due diligence and 10 references called.

That checking is startup due diligence. Here’s what investors and their lawyers actually look at, and how seed differs from Series A. We also cover what Italian companies add (the DURC, for one), which red flags delay or derail deals, and what to prepare now. If you’re only at the idea stage, our beginner’s map from zero to a first round shows where this step sits.

What is startup due diligence, and when does it start?

Due diligence is, as DocSend describes it, the process in which investors confirm that your company really is the promising investment you told them about. The pitch gave the overview. Now the investor and their lawyers check the evidence.

Timing is less tidy than the diagrams suggest. DocSend slots due diligence between two events. The first is the signed term sheet, the document that sets out the main terms of the investment. The second is the moment the investor transfers the money. CRV’s advice to founders: keep the full data room shut until investors near an investment committee decision or start term sheet talks. Plan for both: light questions early, the full request list after signing. More on the document itself in our term sheet explained.

What do investors check? Six areas

Whatever the stage, the questions fall into the same six areas. Below, the Italian document names come first and the English equivalents after. The folder you build to answer them is the data room, and we’ve written a data room checklist for that.

Area	What they ask for (Italian name / English)	Red flag
Legal and corporate	Visura camerale; atto costitutivo e statuto (founding deed and bylaws); verbali di assemblea (meeting minutes); patti parasociali (shareholders’ agreement); list of disputes	Missing contracts; changes agreed but never filed
Cap table and equity	Cap table including options and SAFEs; vesting terms; documents of every past round	Messy equity records
Intellectual property	Marchi, brevetti e domini (trademarks, patents, domains); cessioni dei diritti firmate (signed IP assignments) from employees, founders and consultants	Unsigned assignments; pending IP litigation
Financial and tax	Bilanci depositati (filed accounts); modello finanziario (financial model); estratti conto (bank statements); dichiarazioni dei redditi e IVA (income tax and VAT returns); DURC, if you have employees	Delinquent taxes; unpaid staff or suppliers; numbers that disagree
Commercial	Contratti dei clienti principali (top customer contracts); pipeline; market and competitor analysis; reference calls	One contract with unreasonable risk
Team and tech	Organigramma (org chart); contratti di lavoro (employment agreements); background and references; tech stack, software licences, security practices	A security breach nobody mentioned

Most of it is paper, not product. The deck is how an investor decides your idea deserves a second look. Due diligence is where they find out whether the company behind it is in order. Before this stage they weigh other things, covered in what investors look for in a first-time founder.

Seed vs Series A: what changes?

Kruze Consulting is a US accounting firm for startups. Its view of pre-seed and seed checks: light. The team, the market, the core idea, a few basic financials, a cap table, a simple checklist. At Series A the load grows. Product-market fit gets tested. So do early traction (the first proof that customers want what you sell) and scalability. The paperwork grows with it: detailed financial statements, cash flow projections, unit economics (what you earn and spend per customer), tax returns. Its full checklist asks for three years of statements and returns. A young company simply shows what it has.

How soon does that heavier version arrive? Italy counted 53 Series A rounds in 2025, out of 436 rounds in total (Growth Capital and Italian Tech Alliance). In the US, Carta put the median gap between seed and Series A at 1.9 years in the fourth quarter of 2025. So the deeper checks tend to come roughly two years after a seed round, and they will cover everything in between. Straightening out two years of records in one go is painful. Keeping them straight week by week is not.

How long does due diligence take, and what happens in it?

Averages, remember. Gompers, Gornall, Kaplan and Strebulaev (2020) found 83 days to close, 118 hours of due diligence and 10 references called, and no two deals look alike. DocSend’s own word for the process is time-consuming, sometimes never-ending. Its advice: get your documents ready before you pitch.

There’s no fixed script, but most deals run roughly like this:

1. A request list arrives from the investor’s lawyers.
2. You answer through the data room, document by document. A tidy room cuts the back and forth, as DocSend notes.
3. Reference calls happen in parallel, with people who know you or your product.
4. Questions come back. Some are small, like a missing signature. Some need a fix, like a transfer of quotas that was never registered.
5. The lawyers report to the investor, and the closing documents follow.

What Italian companies add: visura, bilanci and the DURC

None of the US checklists we read mention three Italian items. The first is the visura camerale, which for an SRL lists the shareholders: if it disagrees with your cap table, the list of who owns what, the lawyer will notice. Show the fully diluted version too, with options and SAFEs counted, as Kruze’s checklist asks. The second is the bilanci depositati, the annual accounts filed at the Registro Imprese. The third is the DURC, the Documento Unico di Regolarità Contributiva.

The Ministry of Labour describes the DURC as a certificate of regularity towards INPS, INAIL and the Casse edili where they apply. It’s valid for 120 days and companies request it online with their INPS and INAIL credentials. If you have employees, an investor may ask for it. Mind the clock: one issued on 1 March is out of date before July.

Add the dichiarazioni dei redditi e IVA that your accountant files. Your accountant can also tell you which other compliance certificates make sense in your case.

Red flags that delay or derail deals

The list is short and unglamorous. Kruze names delinquent taxes, missing contracts, messy equity records, unpaid employees or suppliers and pending IP litigation among the issues to disclose, and says security breaches should be disclosed proactively. CRV says missing IP assignments can derail deals and conflicting numbers kill momentum. DocSend warns that one problematic contract can delay closing a round.

Most of these can be fixed before anyone looks. Getting a signature on an old IP assignment, or filing a forgotten quota transfer, is a small job when you do it first. Explaining one that the investor’s lawyer found first is a harder call.

Your due diligence checklist

1. Run the six-area table against your own company and mark every gap.
2. Order a fresh visura camerale and match it to your cap table.
3. Track down signed IP assignments for anyone who built something: employees, founders, consultants.
4. Pull together the filed accounts, the tax returns and the bank statements, plus a current DURC if you have employees.
5. Make a list of your contracts. Begin with the ten biggest customers and anything with unusual terms.
6. List the problems you already know about: a dispute, a late payment, a breach. Put the plan to fix each one beside it, and tell investors before they find out.
7. Come back to this list every quarter: Kruze suggests treating it as an operating tool, not a last-minute scramble.

For the wider picture of a round in Italy, from first cheque to closing, read our guide on how to raise capital for a startup in Italy.

This article is general information, not legal or tax advice. Rules change: check the official sources or ask a professional before you rely on any of it.