What investors ask for in your startup's security due diligence

By the QuantumSec team

When a startup raises a serious funding round, technical due diligence no longer stops at code or architecture review: Series A investors and beyond almost always include a security posture review. Showing up unprepared rarely kills the deal, but it does create friction, slows the close and opens the door to less favorable terms. This guide explains exactly what you'll be asked for and how to prepare each piece in advance.

What documents an investor actually asks for

In most Series A/B rounds, security due diligence asks for four concrete things: a recent penetration test report (ideally from the last 12 months), a documented information security policy, a record of how internal access and permissions are managed, and evidence of an incident response process, even a basic one. If your product handles sensitive data (health, finance, minors), expect specific questions about encryption and data retention.

Why "we've never had a problem" isn't a valid answer

An investor isn't looking for proof that nothing has ever happened: they're looking for evidence you'd know what to do if it did. The absence of a pentest doesn't mean there are no vulnerabilities — it means nobody has looked for them yet. Due diligence analysts know this, and a startup with zero security documentation raises more doubt than one presenting a pentest report with findings already remediated: it shows the team audits and fixes, not that it's flawless.

The real cost of showing up unprepared

It's rarely an outright no. It's a condition precedent clause (closing delayed until findings are fixed), a valuation haircut if critical findings surface during diligence itself, or simply weeks of delay while you scramble to hire someone. Preparing this documentation in advance costs a fraction of improvising it under the pressure of a closing round.

How to prepare with a 6-8 week runway

The order that works best: start with a product pentest (the piece that takes longest to schedule and run), draft the security policy and access management procedure in parallel, and finish with a short incident response plan document. This covers 90% of what a Series A/B investor asks for without needing a formal certification like SOC 2 or ISO 27001, which typically comes at a later stage.

FAQ

Do I need SOC 2 or ISO 27001 for a Series A?

Usually not. Those certifications are typically requested by enterprise clients or investors at later stages (Series B onward). For a Series A, a recent pentest plus basic security documentation is usually enough.

How far ahead of closing should I start?

At least 6-8 weeks, since a quality product pentest usually takes 1 to 3 weeks to run, plus scheduling time with the provider.

What if the pentest finds critical vulnerabilities right before closing?

Better that you find them than the investor's due diligence team. A report showing findings already fixed with re-test evidence builds more confidence than having no report at all.