NDAs are everywhere in dealmaking, but few investors or founders stop to ask the most basic question: how long does an NDA last, and does it actually protect what matters? It’s not a trivial issue. In M&A, venture financing, or commercial partnerships, NDAs don’t just govern legal exposure—they shape timing, control competitive information flow, and signal strategic posture. And yet, many NDAs are recycled boilerplate: signed without scrutiny, enforced selectively, and misunderstood by both parties.

Why does this matter now? Because deals are moving faster. Competitive auctions compress diligence into days, startups raise pre-seed rounds in weeks, and buyers increasingly rely on proprietary pipeline data that may sit in a grey zone. If an NDA expires in 12 months, but a strategic acquirer uses your financial model 13 months later—is that a breach or just sharp elbows? If a VC declines to sign an NDA and sees five other pitches in the same category, what protections remain?

Understanding how long an NDA lasts, what makes it enforceable, and when it actually shapes strategic outcomes is no longer just legal hygiene. It’s a lens into deal control, disclosure pacing, and risk containment in a fast-moving capital market.

How Long Does an NDA Last? Standard Terms vs. Strategic Flexibility

The default answer to “how long does an NDA last?” is deceptively simple: it depends. In most M&A and venture NDAs, the term falls into a few common buckets:

• 12–24 months: The most typical duration, especially in early-stage or asset-light deals
• 3–5 years: Used in IP-heavy transactions or strategic carveouts involving proprietary tech or customer data
• Indefinite (perpetual): Reserved for trade secrets, source code, or sensitive financial disclosures that remain relevant long after a deal falls apart

But duration alone doesn’t tell the whole story. Smart dealmakers match the NDA term to the expected shelf life of the information. In a competitive SaaS M&A process, for example, projected CAC, churn, and LTV data might become obsolete within a year, making a five-year NDA excessive. In contrast, when Intel acquired Habana Labs, the NDA governing chip design details lasted well beyond the deal to ensure core IP protections.

Flexibility also shows up in carve-outs. It’s common to see NDAs that include tiered durations—one year for general commercial info, three years for customer lists, and perpetual protection for algorithms or patented tech. This layering lets the disclosing party protect what really matters, without overreaching and risking pushback or unenforceability.

In some deals, duration becomes a point of negotiation. Strategic buyers may resist long NDA terms if they’re active in the space. Sellers, especially in auctions, may push for longer periods to prevent data leakage. That friction is often resolved through carve-outs, standstill clauses, or narrow definitions of “confidential information.”

Ultimately, the answer to “how long does an NDA last?” depends not just on what’s being protected, but how likely it is to remain sensitive, useful, or actionable in the hands of a competitor.

Enforceability of NDAs in M&A: What Actually Holds Up in Court?

Having a long NDA term doesn’t mean it’s enforceable. In court, what matters isn’t just duration—it’s clarity, scope, and provable harm. And as case law shows, many NDAs break down under real-world stress tests.

Courts often scrutinize whether the confidential information was clearly defined, whether it was truly proprietary, and whether the receiving party acted in bad faith. In Omnicare v. NCS Healthcare (2003), for instance, the Delaware Chancery Court allowed a rival bidder to submit a competing offer during an M&A process—even though the initial NDA included restrictions—because the court found the language vague and the process competitive in nature.

That precedent matters. It means that if your NDA doesn’t precisely define what constitutes “confidential information,” or fails to carve out publicly known or independently developed insights, enforcement becomes difficult. Similarly, NDAs that bar “use” of information but don’t restrict “learning” from it create loopholes. A potential acquirer might not directly copy your financial model, but could apply the insights across other deals without technical violation.

Some courts have also rejected overly long durations as “unreasonable restraints on trade”—especially if the NDA attempts to prevent a party from competing or engaging in other deals in the same space. That’s why perpetual NDAs for general commercial info often fail, even if both parties signed them.

The enforceability risk becomes more pronounced in cross-border deals. NDAs governed by New York or Delaware law may not hold the same weight in EU courts, especially if they conflict with local competition or data privacy statutes.

To actually hold up, an NDA must:

• Clearly define the protected information
• Limit duration to what is proportionate to the sensitivity and value of the data
• Demonstrate harm or unfair advantage from misuse or breach

It’s not about having the longest NDA—it’s about having the tightest, most defensible one when the stakes rise.

Venture Capital NDAs: Why Many VCs Refuse Them—and When They Matter

In the venture world, NDAs are more cultural lightning rod than legal tool. Most institutional VCs—Sequoia, Accel, a16z—won’t sign NDAs at all during the pitch phase. It’s not a red flag. It’s the norm. Founders often push back, but the refusal usually isn’t personal—it’s practical.

Why the resistance? VCs hear hundreds of pitches a year, often from companies in the same space. Signing NDAs across that pipeline could legally expose them to conflicts or restrict future investments. If one startup pitching a novel B2B payments tool requires a signed NDA, it could jeopardize the firm’s ability to invest in a similar company six months later. No fund wants that liability hanging over a future term sheet.

But the blanket refusal doesn’t mean all bets are off. VCs are still bound by reputational risk. Sharing a founder’s sensitive deck or leaking term sheet conversations is the fastest way to get blacklisted. The industry operates on trust, not just contracts.

That said, there are moments when an NDA—or some form of confidentiality agreement—becomes not only acceptable, but advisable. Deep-tech or life sciences companies sharing unpublished patent data, startups disclosing detailed customer contracts, or founders running dual-track processes (venture and M&A simultaneously) may negotiate light-touch NDAs with specific carve-outs.

In those cases, the NDA term is often short—3 to 6 months—and narrowly defined. The focus is on preventing immediate competitive misuse, not policing future investments. Some VCs agree to email-based confidentiality acknowledgments instead of full legal documents—a compromise that protects both sides without triggering compliance overhead.

For founders, the key isn’t demanding an NDA upfront. It’s understanding what needs protection, when to share it, and how to structure disclosure across stages of engagement. Pitch broadly early on; go deep only once there’s meaningful interest and alignment.

Strategic Use of NDAs: Controlling Timing, Disclosure, and Competitive Intelligence

NDAs aren’t just about legal protection—they’re about control. Used strategically, they shape how information flows in a deal process, who sees what and when, and how buyers or investors behave under pressure.

In M&A, NDAs often govern more than just confidentiality. They influence auction dynamics. A seller might provide high-level financials under a general NDA but reserve customer contracts or margin data for shortlisted bidders under a second-tier, more restrictive NDA. This layering prevents early-stage leak risk while maintaining competitive tension.

In dual-track processes—where a company is pursuing both an IPO and a sale—NDAs become time bombs. One party might try to delay signing or negotiating terms until they’ve scoped out the full competitive landscape. Meanwhile, strategic acquirers often push for NDAs early so they can run internal modeling, diligence, or even M&A committee prep before the banker opens the data room.

This control becomes even more important in strategic verticals like defense, healthcare, or financial services, where regulatory scrutiny or customer confidentiality adds layers of complexity. A delayed NDA in those sectors can stall deals by weeks. An overly broad one can trigger anti-trust review.

Done right, NDAs let sellers or startups manage process velocity and filter real interest from noise. But the reverse is also true: a poorly structured NDA can backfire, slow down timelines, and even signal inexperience, especially if it includes restrictive clauses like no-shop periods, broad non-competes, or vague definitions of “confidential material.”

For deal professionals, NDAs are often seen as a formality. But when markets are moving fast, competitors are watching, and valuations swing on sentiment, control over disclosure timing can be a competitive advantage, not just a legal safeguard.

Asking “how long does an NDA last” opens the door to a deeper conversation about control, risk, and trust in dealmaking. Duration alone doesn’t guarantee protection. What matters is enforceability, timing, and the strategic use of disclosure. In M&A, the right NDA shapes auction design and limits competitive leakage. In venture, it sets boundaries without shutting doors. And in every deal, it signals how seriously you manage information flow. The best professionals don’t just sign NDAs—they design them to match context, protect what matters, and control what gets revealed, when, and to whom. Because in today’s fast-moving deal environment, information is currency—and NDAs are how you manage its cost.