When someone asks whether an NDA is enforceable, the honest answer is that it depends on the clauses. Most NDAs are valid and enforceable where they are well-drafted, proportionate, and cover genuine commercial confidentiality. But the same contracts frequently contain individual clauses that English courts will refuse to enforce — a definition of confidential information that is too wide, a duration that bears no relationship to the sensitivity of the information, or a restriction that Parliament has made unlawful by statute. Understanding which conditions void or limit an NDA matters both for the party relying on it and the party asked to sign.
NDASafe is a document preparation service, not a law firm. Our templates are legally reviewed against applicable UK law at the point of release, but every situation is different. Where significant value, unusual risk or a cross-border element is involved, take independent legal advice before you sign.
Void versus unenforceable: the practical difference
English law distinguishes between an NDA that is entirely void — treated as if it never existed — and one that is unenforceable in respect of a particular clause or in particular circumstances. True voidness is rare and typically requires fraud, total absence of consideration, or a fundamentally illegal object. Unenforceability of a specific clause is far more common.
Where a clause is unenforceable, courts apply the doctrine of severance: the offending clause is deleted, and the rest of the NDA is enforced. An NDA with an excessively broad definition of confidential information might have that definition read down by the court, while all other obligations stand. Courts are reluctant to rewrite contracts, but they will sever a clause that can be removed without undermining the remainder.
For NDAs in an employment context, some clauses are not merely unenforceable — they are unlawful. A clause purporting to prevent a worker making a protected disclosure under the Public Interest Disclosure Act 1998 is void as a matter of statute, not merely unreasonable. The distinction matters because a void statutory clause cannot be cured by the parties agreeing otherwise.
Missing or insufficient consideration
An NDA, like any contract, requires consideration from both parties. In most commercial NDA contexts, consideration is unproblematic — both parties are entering a commercial relationship, sharing information, or receiving a benefit that supports the agreement. The standard recital ‘in consideration of the mutual exchange of confidential information and entry into the discussions described below’ is generally sufficient.
Consideration problems arise most often in employment situations. If an employer asks an existing employee to sign a new standalone NDA over work already in progress, and gives nothing new in return, the consideration is weak. The employee is already under implied and express confidentiality obligations; the additional NDA provides no new benefit to them. Courts have occasionally declined to enforce employment NDAs signed in these circumstances.
The practical fix is straightforward: where an NDA is signed by an existing employee or contractor, ensure something of value is given in exchange — a payment, an extension of contract, access to information they would not otherwise receive, or a clear recital tying the NDA to a new and specific disclosure.
Confidential information defined too broadly or too vaguely
The most common source of unenforceability in commercial NDAs is a definition of confidential information that is either too broad or insufficiently certain. Courts require that an obligation be defined clearly enough for the party bound to know what it covers.
A definition that purports to cover ‘all information of any kind’ with no categories, no subject-matter limitations, and no connection to a genuine commercial interest will not be enforced in full. A court may read it down to cover only information that was genuinely confidential in character.
Equally, a definition that is too narrow may fail to protect what the disclosing party needs: a definition covering only written documents marked ‘confidential’ will not extend to verbal disclosures, product demonstrations, or information shared without formal marking.
A robust definition names specific categories (financial data, client lists, pricing, technical drawings, source code, business plans), adds a general catch-all, and includes a mechanism for verbal disclosures — typically a confirmation in writing within a short period.
Duration that is unreasonably long
English courts will not enforce a confidentiality obligation over ordinary commercial information that runs indefinitely or for an unreasonably long period. The underlying principle is that confidentiality should last only as long as the information remains genuinely sensitive — an obligation extending beyond that point serves no legitimate purpose.
For general commercial information (pricing, client lists, business plans, financial data), courts typically view 2–5 years as a reasonable standard term. A 20-year or perpetual obligation over the same category is vulnerable to challenge.
Trade secrets are different. Information that qualifies as a trade secret under the Trade Secrets (Enforcement, etc.) Regulations 2018 can be protected indefinitely while it remains secret — the statute itself provides this. An NDA should distinguish between general confidential information (fixed term) and trade secrets (indefinite while secret).
The practical risk of a single long duration applied to everything is that a court asked to enforce the obligation over trade secrets may be reluctant to do so if the same NDA contains an unreasonable duration over ordinary information — creating unnecessary legal uncertainty.
Clauses that are unlawful under statute
A category of NDA clauses that English law makes void by statute, regardless of what the parties have agreed:
- Preventing protected disclosures (PIDA 1998): A clause that purports to prevent a worker or employee making a qualifying protected disclosure under the Public Interest Disclosure Act 1998 is void. NDASafe's Employee and Freelancer NDAs carry this carve-out as a [mandatory] clause that cannot be removed.
- Preventing reporting to regulators: Any clause that purports to restrict cooperation with the FCA, SFO, CMA, ICO, or any other statutory regulator is void. Regulatory reporting obligations cannot be contracted out of.
- Preventing reporting a criminal offence: A clause purporting to prevent a party reporting a criminal offence to the police or other law enforcement is void as a matter of public policy.
- Preventing victim disclosure (Victims and Prisoners Act 2024): A clause in an employee NDA purporting to prevent an employee reporting harassment, abuse, or a related criminal matter protected under the Victims and Prisoners Act 2024 is void.
- Employment Rights Act 2025 (from commencement, expected 2027): Section 202A of the Employment Rights Act 2025, once commenced, will make void any NDA clause — in a settlement agreement or standalone NDA — that purports to prevent an employee or worker disclosing information about harassment, bullying, discrimination, or other relevant workplace conduct.
Unlike an overly broad definition of confidential information — which a court may sever and read down — a clause that violates a statutory right is void by operation of law. The parties cannot agree to waive the protection. An employee who is told they 'can't' make a protected disclosure because of their NDA is entitled to do so regardless, and the NDA clause cannot be relied upon against them.
Non-compete clauses within an NDA: the restraint of trade test
NDAs sometimes include a non-compete or non-solicitation clause alongside the core confidentiality obligations. These clauses are treated differently from the confidentiality obligation itself: they are post-termination restraints of trade, governed by the principles in Tillman v Egon Zehnder Ltd [2019] UKSC 32.
A non-compete clause is enforceable only if it is reasonable: it must protect a legitimate business interest (trade secrets, client relationships, key staff) and go no further than necessary to protect that interest. A clause too wide in scope, too long in duration, or too wide geographically will not be enforced, and the court may sever it from the remainder of the NDA.
The practical implication: an NDA that includes an unreasonable non-compete is not thereby wholly void. The confidentiality obligations can be severed from the void restraint and enforced independently.
Duress, misrepresentation, and lack of capacity
Like any contract, an NDA can be voidable — capable of being set aside — where it was signed under duress, misrepresentation, undue influence, or without legal capacity.
Duress in an employment NDA context typically means the employer giving the employee no real choice but to sign — no time to consider the terms, no offer of independent legal advice, and the clear implication that refusal will result in dismissal or reputational harm. The minimum 10-day reflection period for settlement agreements exists precisely to address this pressure.
Misrepresentation arises where one party is induced to sign by a false statement of fact. If an employer represents that a settlement NDA ‘doesn’t prevent you disclosing anything important’ when it is intended to suppress a protected disclosure, the misrepresentation vitiates consent.
Lack of capacity is rare in commercial NDA contexts but can arise where a signatory was incapacitated at the time of signing or did not understand the document they were signing.
NDASafe's Employee NDA includes [mandatory] carve-outs for whistleblowing (PIDA 1998), victim reporting (Victims and Prisoners Act 2024), and regulatory disclosure — clauses that cannot be removed without making the NDA unlawful. The Mutual NDA and One-Way NDAs are appropriate for commercial contexts where no employment relationship is involved. £29 each or £79 for all eight variants — editable Word documents delivered instantly.