Do NDAs expire?

Emily Gordon BrownLegal Assessment Specialist @ Lawhive

Updated on 14th February 2025

Non-disclosure agreements (NDAs) help protect confidential information in business and legal settings. But, do they ever expire? Generally, the length of an NDA depends on the terms of the agreement. Some have a clear end date, while others can remain in effect indefinitely. Whether you're signing or enforcing an NDA, understanding how long it lasts - and what happens when it ends - is essential.

What is a non-disclosure agreement (NDA)?

A non-disclosure agreement (NDA) is a legally binding contract that prevents one or more parties from sharing confidential information with others. NDAs are commonly used in business deals, employment contracts, intellectual property protection, and legal settlements to keep sensitive details private.

Types of NDAs

There are two main types of NDAs:

• Unilateral NDA: One party shares confidential information, and the receiving party agrees to keep it private. This is common in employment contracts and business negotiations.

• Mutual NDA: Both parties exchange confidential information and agree not to disclose it. This is often used in partnerships, mergers, or joint ventures. Learn more in our guide to mutual NDAs.

What do NDAs protect?

NDAs can cover a wide range of sensitive business information, including:

• Trade secrets and proprietary processes

• Business strategies and financial details

• Client and supplier information

• Product development plans

How long do NDAs last in the UK?

The duration of an NDA depends on the terms specified in the agreement. NDAs can include:

• Fixed-term NDAs: These agreements specify a set duration, such as one, five, or ten years. Once the period expires, confidentiality obligations end. Fixed-term NDAs are common in business deals where confidentiality is required for a limited period, such as during negotiations or while a product is under development.

• Indefinite NDAs: Some NDAs have no expiry date and require confidentiality to be maintained indefinitely. These are often used for trade secrets, proprietary formulas, or other sensitive information that must remain confidential for as long as the information remains commercially valuable. However, an indefinite NDA must be reasonable and justifiable in scope to be enforceable.

• Event-based NDAs: Some NDAs remain in effect until a specific event occurs, such as the conclusion of a business deal, the completion of a project, or the public disclosure of the information by the disclosing party. These NDAs are useful for protecting information only while it remains sensitive or competitive.

• Employment-related NDAs: In many employment agreements, NDAs last for the duration of the employment and continue for a defined period after the employee leaves, typically six months to two years. However, UK courts may not enforce post-employment NDAs that excessively restrict a former employee’s ability to work in their field.

• Government and classified information NDAs: NDAs signed for government or classified work may have their duration set by legislation, and in some cases, they may remain enforceable for decades, even after employment ends.

If an NDA does not specify an expiry date, its enforceability will depend on whether it is considered reasonable under UK law. Courts may consider the length of the restriction and whether indefinite confidentiality is necessary to protect the information. If an NDA imposes an excessive restriction without justification, a court may rule it unenforceable or reduce its duration.

Do NDAs ever expire?

In most cases, NDAs will expire when:

• The time period stated in the agreement has passed.

• The confidential information becomes publicly available through legal means.

• The agreement is mutually terminated by the parties involved.

• A court deems the NDA unreasonable or unenforceable due to excessive duration or broad restrictions.

However, some NDAs may contain clauses that require confidentiality to be maintained indefinitely, particularly when dealing with trade secrets or proprietary technology. Even in such cases, an indefinite NDA could be challenged in court if deemed unreasonable or unfairly restrictive.

💡Top tip: Always review an NDA carefully before signing. If there's no clear expiry date or the confidentiality obligations seem excessive, seek legal advice from an NDA solicitor to ensure the agreement is fair and enforceable.

Do they expire after death?

The enforceability of an NDA after death depends on the terms of the contract and the nature of the confidential information. In general:

• If the NDA was signed by an individual (such as an employee), confidentiality obligations may end upon their death unless otherwise stated.

• If the NDA was part of a corporate agreement, the obligation to maintain confidentiality may continue even after the death of an individual involved.

• In cases where confidential information is a trade secret, legal heirs or estate representatives may still be bound by the NDA.

UK courts may consider whether it is reasonable to enforce an NDA after a party's death, especially if there is no ongoing commercial or legal interest in keeping the information confidential.

Re-cap: Do NDAs last forever?

NDAs do not always last forever. While some agreements specify a fixed-term duration, others are designed to be indefinite. However, even indefinite NDAs must be reasonable and justifiable under UK law. Key takeaways include:

• Most NDAs have an expiry date outlined in the contract.

• If an NDA does not specify an end date, courts will assess its reasonableness.

• Confidentiality may continue after death in certain cases, particularly for corporate agreements and trade secrets.

• NDAs cannot prevent disclosure of information that is already public or protect against illegal activities.

FAQ

Can an NDA be enforced indefinitely?

Yes, but only if the duration is considered reasonable. Courts may not uphold indefinite NDAs if they impose excessive restrictions on an individual’s rights.

Can I challenge an NDA if it does not have an expiry date?

Yes, if an NDA is excessively broad or unfair, it may be challenged in court for being unreasonable or unenforceable.

Does an NDA expire if the confidential information becomes public?

Yes, if the information is legally made public, the NDA may no longer be enforceable.

Can an NDA extend beyond employment?

Yes, NDAs often continue to be enforceable after employment ends, but the duration must be reasonable.

Final thoughts

NDAs are useful tools for protecting confidential information, but their enforceability depends on clear terms and reasonable duration. While some NDAs have fixed expiry dates, others may last indefinitely under certain circumstances. If you are signing or enforcing an NDA, it is advisable to seek legal advice to ensure the agreement is fair, reasonable, and legally binding.

Need expert legal support for your business? Get a fixed-fee quote today and see how our specialist small business solicitors can help.

References

• Non-disclosure agreements from Gov.UK

Fact-checked by Daniel McAfeeHead of Legal Operations @ Lawhive & Practising Solicitor