An NDA, or non-disclosure agreement, is a legally binding contract in which one or both parties promise not to share specified information with anyone outside the agreement. Companies use them during hiring, pitches to investors, partnership talks, and mergers to keep sensitive data from reaching competitors. The document looks simple. What determines whether it actually works are the clauses inside it and the laws that sit on top of it.
The Two Types of NDAs
Every NDA has a disclosing party (the one sharing information) and a receiving party (the one promising to keep it quiet). Which role you’re in dictates which form of agreement you should be signing.
A unilateral NDA runs one way. An employer sharing trade secrets with a new hire, a startup pitching to an investor, or a company bringing in an outside contractor who needs system access all fit this pattern. One side discloses, the other side stays silent.
A mutual NDA protects both sides equally. Joint ventures, merger negotiations, and co-development deals typically call for mutual agreements because each side is handing over information the other could exploit. Both parties act as discloser and receiver at once, and both carry the same restrictions.
The choice matters more than people realize. Signing a unilateral NDA when your own side is also sharing something valuable leaves your information unprotected.
What an Enforceable NDA Contains
A signature alone doesn’t make an NDA stick. Vague or lopsided agreements get narrowed or tossed. A few clauses do most of the work.
A Specific Definition of Confidential Information
The definition is the heart of the contract. A common approach limits protection to information disclosed in writing and marked “confidential,” or disclosed verbally and confirmed in writing within a set window, often 30 days. Another approach covers anything the receiving party knows or should reasonably know is confidential.
Overly broad definitions backfire. An NDA that tries to make everything confidential, including publicly available information or generic industry knowledge, is the kind of agreement courts cut back or void outright. Both parties should be able to identify what’s covered without guessing.
Permitted Use
The agreement should state what the receiving party is actually allowed to do with the information. Evaluating a potential acquisition is a permitted use. Building a competing product using the same data is not. Without a clear purpose clause, the receiver can argue any use was implicitly allowed.
Duration
Many NDAs set a fixed confidentiality period of two to five years. Trade secrets can justify indefinite protection, but only as long as the owner takes reasonable measures to keep the information secret and the information retains economic value because it isn’t publicly known. A duration that outlasts the information’s real-world value invites a court to shorten it.
Consideration
Like any contract, an NDA needs consideration: each side has to get something of value for their promise. For a new hire, the job is usually enough. For an existing employee asked to sign mid-employment, it gets harder. Some courts require something beyond continued employment, such as a bonus, a promotion, or access to new information. An NDA signed without adequate consideration is vulnerable from the moment it’s signed.
Return or Destruction of Materials
Standard agreements require the receiving party to return or destroy all physical and digital copies of confidential materials when the relationship ends or the NDA expires, including notes, summaries, and anything derived from the original information. Without this clause, a former employee or ex-partner can sit on sensitive data indefinitely.
What an NDA Can’t Cover
Some categories of information fall outside NDA protection as a matter of standard contract law, whether or not the document says so.
- Publicly available information. If information is already in the public domain through no fault of the receiving party, the NDA can’t restrict its use. The same applies to information that becomes public later, as long as the receiving party wasn’t the leak.
- Prior knowledge. If the receiving party can show they already knew the information before signing, they aren’t bound to treat it as confidential.
- Third-party sources. Information received independently from someone with no confidentiality obligation to the disclosing party is excluded.
- Independent development. If the receiving party develops the same information on their own without relying on what was disclosed, the NDA doesn’t reach that independent work.
Well-drafted agreements list these carve-outs explicitly, but courts recognize them even when the contract is silent. NDAs protect genuinely secret information, not information the discloser merely wishes were secret.
Laws That Override an NDA
Federal law blocks enforcement of NDAs in several situations, no matter what the contract says.
Whistleblower Immunity
Under the Defend Trade Secrets Act, an individual cannot be held criminally or civilly liable for disclosing a trade secret to a government official or an attorney if the disclosure is made in confidence and solely to report a suspected violation of law. The same immunity covers disclosures made in sealed court filings as part of a lawsuit.1Office of the Law Revision Counsel. 18 USC 1833 – Exceptions to Prohibitions Federal agencies require that NDAs include language acknowledging employees’ rights to report violations to inspectors general, communicate with Congress, and engage in other protected whistleblower activity.2U.S. Marshals Service. Whistleblower Protection and Non-Disclosure Policies, Forms, or Agreements
Sexual Harassment and Assault Disputes
The Speak Out Act, at 42 U.S.C. Chapter 164, makes non-disclosure and non-disparagement clauses judicially unenforceable when they relate to sexual assault or sexual harassment disputes.3Office of the Law Revision Counsel. 42 USC Chapter 164 – Speak Out Act It applies to pre-dispute agreements, so someone who signed an NDA before any harassment occurred can still speak publicly about what happened. It does not retroactively void settlement agreements reached after a dispute has already arisen.
Employee Rights Under the NLRA
The National Labor Relations Board has held that NDAs and confidentiality clauses in severance agreements cannot be so broad that they prevent employees from discussing wages, working conditions, or other activity protected by Section 7 of the National Labor Relations Act. In its 2023 McLaren Macomb decision, the Board found that merely offering an employee a severance agreement with overbroad confidentiality or non-disparagement terms is itself an unfair labor practice.4National Labor Relations Board. Board Rules That Employers May Not Offer Severance Agreements Requiring Broad Waiver of NLRA Rights An NDA that stops you from talking to coworkers about pay or complaining to a government agency about unsafe conditions is unlikely to hold, even if you signed it voluntarily.
Court Orders and Subpoenas
An NDA cannot block someone from testifying when compelled by a court or responding to a lawful subpoena. A clause purporting to forbid court-ordered testimony is unenforceable because the court’s authority to obtain evidence overrides private agreements. Most well-drafted NDAs include a compelled-disclosure exception that requires the receiving party to notify the discloser promptly, giving them a chance to seek a protective order or move to quash before anything is handed over.
What Happens If Someone Breaks an NDA
When the receiving party leaks protected information, the discloser has several ways to respond. The severity depends on what was taken and how much damage followed.
Money Damages
The usual remedy is a breach-of-contract lawsuit for the financial harm caused by the leak. When the NDA covers trade secrets, the Defend Trade Secrets Act supplies a federal cause of action. A court can award damages for actual losses plus any unjust enrichment the violator gained, or alternatively impose a reasonable royalty for the unauthorized use.5Office of the Law Revision Counsel. 18 USC 1836 – Civil Proceedings
Some NDAs include liquidated damages clauses setting a predetermined dollar amount for each violation. These hold up only when actual damages would be genuinely hard to calculate and the stated amount is a reasonable estimate of the expected loss. A number that reads as punishment rather than compensation gets struck down as an unenforceable penalty.
Injunctions
Money often isn’t enough when the information is actively spreading. The disclosing party can ask a court for an injunction ordering the violator to stop any further disclosure. Under the DTSA, courts can also require affirmative steps to protect the trade secret, such as recalling distributed materials.5Office of the Law Revision Counsel. 18 USC 1836 – Civil Proceedings Injunctions are the fastest way to contain damage before it becomes irreversible.
Enhanced and Criminal Penalties
When trade secret misappropriation is willful and malicious, courts can award exemplary damages up to twice the compensatory damages, plus reasonable attorney’s fees.5Office of the Law Revision Counsel. 18 USC 1836 – Civil Proceedings In the most serious cases, trade secret theft triggers federal criminal charges. A conviction for stealing trade secrets related to interstate commerce carries fines and up to 10 years in prison.6Office of the Law Revision Counsel. 18 USC 1832 – Theft of Trade Secrets Criminal prosecution is rare, and the cases that do get charged tend to involve deliberate corporate espionage or systematic downloads of files before a jump to a competitor.
Why NDAs Get Thrown Out
Plenty of signed NDAs don’t survive challenge. The common failure modes:
- No consideration. The receiving party got nothing of value in exchange for signing. This usually surfaces when an employer asks a current employee to sign a new NDA with nothing offered beyond keeping their job.
- Overly broad scope. The definition of confidential information is so vague it could cover anything. Courts expect specificity.
- Unreasonable duration. A 20-year confidentiality obligation on information with a two-year useful life invites skepticism.
- Illegal purpose. An NDA designed to conceal criminal activity, fraud, or regulatory violations is void as against public policy.
- Violation of employee rights. Under McLaren Macomb, agreements that broadly restrict employees from discussing wages or working conditions violate federal labor law.4National Labor Relations Board. Board Rules That Employers May Not Offer Severance Agreements Requiring Broad Waiver of NLRA Rights
Some states let courts “blue pencil” an overbroad NDA by narrowing its terms. Others void the whole thing. Getting the scope right from the start is safer than counting on a judge to repair sloppy drafting.