Definition
A non-disclosure agreement (NDA), also called a confidentiality agreement, is a legally binding contract in which one or more parties agree to keep specified confidential information secret and not to disclose or misuse it. NDAs allow people and businesses to share sensitive information—such as trade secrets, financial data, or product plans—while creating a legal obligation that protects that information from being leaked to competitors or the public.
Legal Meaning
A non-disclosure agreement is a contract whose central purpose is to protect confidential information. Like any contract, an NDA must satisfy the basic requirements of offer, acceptance, and consideration to be enforceable. In employment and commercial settings, the opportunity to enter a relationship or receive valuable information often supplies that consideration.
NDAs are a foundational tool in business law. They are used before mergers and acquisitions, when hiring employees who will access proprietary systems, when engaging contractors or vendors, and when pitching ideas to investors. The agreement defines what counts as "confidential information," imposes duties on the receiving party to protect that information, and specifies how long those duties last.
A well-drafted NDA does more than say "keep this secret." It identifies the parties, describes the permitted purpose for which the information may be used, carves out exceptions (such as information already public or independently developed), and sets out remedies if the agreement is breached. Because an NDA is interpreted under contract law, its precise wording controls. Ambiguous or overbroad definitions can make the agreement difficult to enforce.
Key Points
- An NDA is a contract that protects confidential information from disclosure
- Unilateral NDAs protect one party's information; mutual NDAs protect both
- The agreement must clearly define what counts as confidential information
- Common exclusions cover public information and independently developed material
- NDAs typically set a defined term, though trade secrets can be protected longer
- Breach can lead to a lawsuit for damages and an injunction to stop disclosure
- Consideration is required, just as with any enforceable contract
- Some states limit NDAs that would silence reports of unlawful conduct
Real-World Example
A startup founder wants to pitch a new app concept to a software development firm before hiring it to build the product. Because the concept and its underlying algorithms are the startup's most valuable asset, the founder asks the firm to sign a unilateral NDA first. Under the agreement, the firm may use the disclosed information only to evaluate and perform the development work, and it agrees not to share the concept with anyone else or build a competing product.
If the firm later leaks the concept to a competitor or uses it to launch its own version, the startup could sue for breach of the NDA, seek monetary damages for the harm caused, and ask a court for an injunction to stop further use—particularly if the information also qualifies as a protected trade secret.
Unilateral vs. Mutual NDAs
| Feature | Unilateral (One-Way) NDA | Mutual (Two-Way) NDA |
|---|---|---|
| Who discloses | Only one party shares confidential information | Both parties share confidential information |
| Who is bound | The receiving party | Both parties |
| Common use | Employer to employee; founder to vendor | Two companies exploring a deal or partnership |
| Negotiation | Often simpler, one-sided protection | More balanced; each side wants fair terms |
| Typical setting | Hiring, pitching ideas, sharing samples | Mergers, joint ventures, co-development |
Key Clauses in an NDA
Most NDAs share a set of standard provisions, even though the wording varies:
Definition of Confidential Information
The heart of the NDA. It specifies exactly what is protected—whether marked documents only, or all information disclosed under the agreement.
Exclusions From Confidentiality
Information that is already public, was known before disclosure, is independently developed, or is lawfully received from a third party is usually excluded.
Permitted Use and Obligations
The agreement limits how the receiving party may use the information and requires reasonable steps to keep it secure.
Term and Survival
The NDA states how long confidentiality obligations last. Obligations often survive even after the broader relationship ends.
Remedies
Many NDAs expressly allow the disclosing party to seek injunctive relief, recognizing that money alone may not undo the harm of a leak.
NDAs vs. Other Restrictive Agreements
An NDA is sometimes confused with related agreements. A non-compete agreement restricts where and for whom a person can work, while an NDA only restricts the use and disclosure of information. A non-solicitation clause limits soliciting customers or employees. These provisions are often combined in a single document, but they serve different purposes and face very different rules on enforceability—non-competes in particular are sharply limited or banned in several states, whereas NDAs are generally enforceable when reasonable.
Related Terms
Need an NDA Drafted or Reviewed?
A business attorney can tailor a confidentiality agreement to your situation and make sure it is enforceable.
Find a Business LawyerWhen You Need a Lawyer
NDAs look simple but contain important details that affect whether they will hold up. You should consult an attorney if:
- You are about to share trade secrets, source code, or other high-value information
- You are asked to sign an NDA whose definitions seem overbroad or one-sided
- The NDA is bundled with non-compete or non-solicitation terms
- You believe someone has breached an NDA and disclosed your confidential information
- An NDA appears to limit your ability to report unlawful conduct
An attorney can negotiate fair terms, draft clear definitions, and pursue or defend a claim if a breach occurs. To understand what legal help costs, see our guide on understanding legal fees.
Frequently Asked Questions
What is the difference between a mutual and a unilateral NDA?
In a unilateral (one-way) NDA, only one party discloses confidential information and the other party agrees to protect it—common when an employer shares secrets with an employee. In a mutual (two-way) NDA, both parties share confidential information and both agree to protect what they receive—common when two businesses explore a partnership or merger.
What does an NDA actually protect?
An NDA protects confidential information that the parties define in the agreement, such as trade secrets, customer lists, financial data, product designs, source code, business plans, and other proprietary material. Information that is already public, independently developed, or lawfully obtained from another source is usually excluded from protection.
How long does an NDA last?
The term varies by agreement. Many NDAs run for a fixed period, often two to five years after signing or after the business relationship ends. Trade secrets may be protected for as long as they remain secret. The right duration depends on the type of information and the parties' needs, and overly long terms can sometimes be harder to enforce.
What happens if someone violates an NDA?
A breach of an NDA can expose the violator to a lawsuit for damages caused by the disclosure and, where appropriate, an injunction ordering them to stop using or sharing the information. If the disclosed information qualifies as a trade secret, additional remedies may be available under state or federal trade secret law. Remedies depend on the contract terms and the harm caused.
Are NDAs enforceable?
Generally yes, when they are reasonable in scope, protect genuinely confidential information, and are supported by consideration. However, courts will not enforce an NDA used to conceal illegal activity, and some states limit NDAs that would prevent employees from disclosing unlawful conduct such as harassment or discrimination. Enforceability ultimately depends on state law and the agreement's terms.