NDA for Startups: When to Sign and When to Skip

A non-disclosure agreement (NDA) is a contract where one or both sides promise to keep shared information confidential and use it only for a stated purpose. Startups should use one when sharing real secrets with a specific person who needs them, and skip it when the ask would cost more than the secret is worth, such as with most investors.

Startup lifecycle A to Z · Letter N · Stage: Build

By the Revolutionary Startups editors · Reviewed 11 November 2026 · 12 min read · 2,724 words

What an NDA is, and what it is not

A non-disclosure agreement, or NDA, is a contract about information. One party (or both) agrees that what it learns from the other will be kept confidential and used only for a defined purpose, such as evaluating a deal or doing a job. If the promise is broken, the contract gives the other side something to enforce.

That is the whole job. An NDA does not create IP rights. It does not stop someone from independently developing the same idea. It does not make an unprotected idea into a trade secret. It does not remove the need to manage trade secrets with real safeguards, which is a separate subject we cover in our guide to trade secrets and NDAs. This guide stays with the document itself: what each clause does, when to ask for one, and when asking is a mistake.

What an NDA protects

• Information you share that is not public and that you identify as confidential, within the limits the contract sets.
• Your ability to argue later that you took reasonable steps to keep valuable information secret, which matters for trade secret status.
• A clear agreement about what the other side may do with what you share.

What an NDA does not protect

• Information that is already public, or that becomes public through no fault of the recipient.
• Ideas the recipient already knew, or develops on their own without using your information.
• Anything you did not share, or shared without any marking or description where the contract requires it.
• You, if you cannot afford to enforce it. A promise is only as strong as your ability to sue, and suing costs money.

A signed NDA also does not stop leaks that happen through carelessness on your side, such as posting a demo link publicly. Treat it as one layer of protection, not a lock.

When to ask for an NDA, and when not to

The most useful question is not "should I have an NDA?" but "what am I giving away, and who needs it?" A founder who asks everyone to sign wastes time and sometimes signals inexperience. A founder who asks no one risks losing real secrets.

Situations where an NDA usually makes sense

• Sharing source code, unpublished technical designs, formulas, algorithms or datasets with a contractor, a manufacturer or a technical partner.
• Sharing non-public customer, pricing or financial details with a potential partner or acquirer in serious talks.
• Letting a potential co-founder, advisor or early hire see core know-how before they join. (Once someone is on the team, an employee or contractor IP agreement does more of the work.)
• Demoing an unreleased product to a possible distributor or customer.

Situations where asking for an NDA often backfires

• Early investor meetings. Investors see many pitches, often in the same space, and many routinely decline to sign NDAs for a first conversation. Whether a particular investor will sign varies, but asking up front can end the meeting. Share what you can without revealing core secrets, and read our guide to protecting your startup idea when pitching.
• Casual conversations about a general idea. An idea with nothing behind it is hard to protect with any contract, and people will not sign for it.
• Customer discovery calls. You are asking questions, not revealing secrets. Keep the details light.
• Public information. If you have already launched or published it, there is nothing left to protect.

The practical rule: if the information would hurt you if a competitor had it, and the other person needs it to do something useful, use an NDA. If the information is not that sensitive, or the person cannot reasonably agree, adjust what you share instead of fighting over paper.

Who to ask: a decision table

Use this as a quick guide. It describes common practice, not a rule, and the right answer depends on how sensitive your information is.

If a counterparty refuses to sign and still wants to see everything, that tells you something. You can share in stages: start with a high-level description, then reveal more as trust and commitment grow.

Clause by clause: reading an NDA

Most NDAs are short, and most disputes come from a handful of clauses. This walkthrough follows the usual order of a standard NDA.

1. Definition of confidential information

This clause decides what is covered. A broad definition covers anything shared in any form, whether or not it is marked. A narrow one covers only information marked "confidential" or confirmed in writing within a short period after a verbal disclosure. Broad is better for the discloser, but too broad can be unreasonable and harder to enforce. If you are the discloser, make the definition cover the kinds of information that matter (code, designs, plans, customer data) and include information that a reasonable person would understand to be confidential. If you are the recipient, check that you can actually tell what is covered.

2. Exclusions

Standard exclusions remove information that:

• is or becomes public without the recipient breaking the agreement;
• the recipient already knew, as shown by its records;
• the recipient receives from a third party who had the right to share it; or
• the recipient develops independently without using the confidential information.

These are normal and fair. Watch for unusual additions, such as excluding anything "generally known in the industry," which can swallow the whole agreement.

3. Permitted use and permitted people

The recipient may use the information only for a stated purpose, such as "evaluating a possible partnership." A vague purpose ("business purposes") weakens the agreement. The clause should also say who can see the information: employees, advisors and contractors with a need to know, who are bound by similar duties. Keep the list short.

4. Term and survival

See the next section. The key point is that the agreement may end for new disclosures at one time, while the duty to protect information survives for a longer period.

5. Return or destruction

On request or when the deal ends, the recipient returns or destroys materials and confirms in writing. Check for a carve-out that lets the recipient keep backup copies, and ask that backups remain protected.

6. Remedies

Many NDAs state that a breach may cause harm that money cannot fix, so the discloser can ask a court for an order (an injunction) to stop it, in addition to damages. This language helps, but it does not guarantee a court will agree. Some NDAs also include fee-shifting, so the loser pays legal costs, and a governing law and venue clause that picks the state and courts.

7. No license, no obligation to deal

A good NDA says that sharing information does not give the recipient any rights in it, and that neither side has to make a deal. This avoids arguments later that you granted a license by showing your work.

Residuals clauses and why they matter

A residuals clause says the recipient may freely use information that stays in the unaided memory of its people after they see your information, as long as they do not deliberately memorize it. It sounds harmless and is common in some technology and corporate forms. For a startup, it can quietly gut the NDA.

Here is why. If an engineer at a large company reads your design, remembers its structure and later builds something similar, a residuals clause may allow it, even though the NDA technically stays in place. "Unaided memory" is hard to prove or disprove, so disputes are hard to resolve.

What to do about it

• If you are the discloser: strike the clause. If the other side insists, narrow it: exclude trade secrets, source code, algorithms and anything that is covered by your patents or copyrights, and make clear that no license to those rights is granted.
• If you are the recipient: a limited residuals clause may protect your team from claims that ordinary learning breached the NDA. Keep it narrow and fair.
• In any case: decide before you sign what you would be comfortable having the other side remember.

Mutual vs one-way NDAs, and how long an NDA should last

Mutual or one-way

A one-way (unilateral) NDA protects one party's information: you share, they receive. A mutual (bilateral) NDA protects both sides, which suits partner talks, acquisitions and pilots where both sides disclose. Mutual agreements are often faster to sign, since neither side feels singled out. But if only you are sharing, a mutual form still works; just check that the obligations you accept are ones you can follow.

How long should an NDA last?

There is no single standard. Common structures, which vary by industry and by what the information is, include:

For information you hope will remain a trade secret, a short fixed term can undermine your position: once it ends, the recipient is free to share it, and you may find it hard to argue that you took reasonable steps to protect it. On the other side, recipients often resist indefinite terms for ordinary business information. A lawyer can set the right balance for what you are sharing. Wysebridge's free guide to trade secret law explains what qualifies and how reasonable measures work.

Template or lawyer: how to get an NDA in place

A template is fine for many routine uses. A lawyer is worth the cost for the high-stakes ones. How to decide:

Terms and law vary, so a lawyer should confirm what fits your case. If you need a patent attorney or agent for related work, Wysebridge's directory of USPTO-registered patent attorneys and agents is built from the public roster; for a general contract or trademark lawyer, use state bar directories and referrals.

Common mistakes with NDAs

• Asking for an NDA too early. First meetings with investors or customers rarely need one, and the request can cost goodwill.
• Treating the NDA as the whole plan. Without access controls, marking and need-to-know sharing, the contract is weak evidence of secrecy.
• Vague definitions. If neither side can tell what is covered, nobody is protected.
• Signing after disclosing. Get it signed first.
• Ignoring residuals and purpose clauses. A broad residuals clause or a loose purpose can undo the rest.
• No IP terms with contractors. A contractor can keep confidential information secret and still own what they build, unless you have an assignment. See IP assignment agreements.
• Never reviewing the NDA you signed. Some NDAs bind you for years and restrict what you can build. Track the ones you signed.
• Filing patents too late. Sharing an invention under an NDA does not stop the clock on certain patent deadlines from other kinds of public disclosure. Learn the basics in the patent process for startups.

Where this fits in the startup lifecycle

NDAs matter most in the Build stage, when you start sharing real work with contractors, partners and early customers. The guide before it in the series is trademark, copyright and patent notices. The guide after it is open source licenses for startups, which covers what to check before putting third-party code in your product. See the whole series in the startup lifecycle A to Z.

If you want to learn the legal ideas underneath, Wysebridge's self-study course on U.S. patent, trademark, copyright and trade secret law covers them in order. An attorney should draft or review any NDA that protects something you cannot afford to lose.

Frequently asked questions

When should a startup use an NDA?

Use one when you are about to share specific, non-public information that would hurt you if a competitor had it, with a person who needs it to do something useful, such as a contractor, partner or acquirer. Skip it for general ideas, public information and most early investor meetings.

Will investors sign an NDA?

Many investors decline to sign NDAs for pitches, because they see many companies and want to avoid claims. Practices vary by investor and stage. Share what you can without revealing core secrets, and expect confidentiality terms later in diligence, often on their form.

What is the difference between a mutual and a one-way NDA?

A one-way NDA protects only one party's information. A mutual NDA protects both sides, which fits partner talks and acquisitions where both disclose. Pick the one that matches who is actually sharing, and check you can comply with every duty you accept.

How long should an NDA last?

There is no standard. Many NDAs use a fixed number of years, with trade secrets protected for as long as they stay secret, and some use an indefinite term for core secrets. A short term for crown-jewel information can weaken your position, so ask a lawyer to match the term to the information.

What do NDAs not protect?

They do not cover public information, things the recipient already knew or developed independently, or ideas you never shared. They also do not create IP rights, stop independent invention, or help much if you cannot afford to enforce them. They work best with good secrecy practices.

Can I use an NDA template, or do I need a lawyer?

A reputable template can work for routine, low-risk uses. For source code, core technology, or a counterparty's own form, have a lawyer draft or review it. Check the definition, purpose, term and residuals clauses in any case.

Should I use an NDA with a contractor?

Yes, before they see anything sensitive, and ideally as part of the services agreement. Pair confidentiality with a written IP assignment, since confidentiality alone does not give you ownership of what the contractor creates.

Key terms on this page

• NDA
• Trade Secret
• Co-Founder
• Cap Table
• IP Assignment
• Founders' Agreement
• Copyright
• Acquisition
• Trademark

Keep reading

• Trade Secrets for Startups: NDAs and Secrecy Steps IP guideTrade secrets for startups: what qualifies, what reasonable secrecy measures look like, when to use an NDA, and whether investors will sign one.
• How to Protect Your Startup Idea When Pitching GuideHow to protect your startup idea when pitching: what the law protects, why investors skip NDAs, staged disclosure, and what to keep out of a pitch deck.
• Employee Invention Assignment Agreements for Startups GuideEmployee invention assignment agreement basics: what employees, contractors and interns sign on day one so your startup owns the IP they create.
• IP Ownership in a Partnership: Joint Development Guide GuideIP ownership in a partnership: background vs foreground IP, joint development agreements, co-owned patent risks and a larger-partner checklist.
• Open Source Licenses for Startups: A Practical Guide GuideOpen source licenses for startups explained: permissive vs copyleft, MIT vs Apache vs GPL, what triggers obligations, license scanning and investor diligence.

Learn more from Wysebridge

Wysebridge owns, operates and sponsors Revolutionary Startups, so these are links to its own free resources and directories. Read the disclosure.

• Wysebridge trade secret law guideFree guide to trade secrets: what qualifies, the DTSA and UTSA, NDAs and misappropriation.
• Wysebridge U.S. IP law courseA 20-chapter self-study course on U.S. patent, trademark, copyright and trade secret law; module 1 is free.
• Wysebridge IP glossaryDefinitions of trademark, patent and USPTO terms, from specimens to the Madrid Protocol.

Part of Protecting Your Startup · All guides · Glossary

Sources

• USPTO: Trademark, patent, or copyright?

General information, not legal, tax or financial advice. Reviewed 11 November 2026.