An NDA, or non-disclosure agreement, is a contract in which one or both parties agree to keep certain information confidential and use it only for an agreed purpose. If you are asking what is an NDA in the UK, the plain answer is that it is a legally binding promise not to share or misuse someone's confidential information. You need one whenever you are about to reveal something sensitive, a business plan, financials, technical detail, customer data, to someone who is not already bound to keep it secret: a potential partner, contractor, investor or co-founder. An NDA is a contract under England and Wales law and is generally enforceable, but it protects confidentiality only; it does not, on its own, transfer intellectual property. This is general information, not legal advice.
The word "NDA" gets used loosely, so it helps to be precise about what the document is and is not. It is a confidentiality contract. It is not a substitute for an IP assignment, an employment contract, or a commercial agreement. Used at the right moment it lets sensitive conversations happen safely; used as a catch-all it creates false comfort. This guide explains the two main types, when you actually need one, and the limits worth understanding before you rely on it.
What an NDA is (and the two main types)
At its heart an NDA does a simple thing: it defines what information is confidential, says the recipient must keep it confidential and use it only for a stated purpose, sets how long the duty lasts, and spells out the standard exceptions (information that is already public, already known, independently developed, or required to be disclosed by law).
There are two common shapes.
A one-way (unilateral) NDA is for when only one side is disclosing. A business hands sensitive material to a contractor, a recruiter or a supplier who is only receiving it. The obligations run in one direction. Our one-way NDA template guide covers this case.
A mutual (bilateral) NDA is for when both sides will share confidential information: two companies scoping a partnership, a founder and a potential co-founder, an agency and a client swapping roadmaps. The obligations are symmetrical. Our mutual NDA template guide walks through it. This is the more common case in practice, because most real conversations involve both parties revealing something.
Choosing the right shape matters. A one-way NDA presented to someone who is also disclosing feels one-sided and slows the deal; a mutual NDA where only one party ever discloses is harmless but unnecessary. Match the document to the actual flow of information.
When do you actually need an NDA?
An NDA earns its place when three things are true at once: the information is genuinely confidential, the other side is not already bound to protect it, and you are about to share it before a fuller agreement exists. Common triggers:
- Exploring a partnership or deal where you will exchange commercially sensitive information before any contract is signed.
- Engaging a contractor, freelancer or agency who will see your systems, data or plans.
- Early hiring conversations with a potential co-founder or senior hire who needs to understand the business.
- Talking to suppliers or manufacturers about a product that is not yet public.
- Selling or raising where a counterparty will review sensitive material, though note that many early-stage investors decline to sign NDAs to view a first deck, a tension we cover in should you make investors sign an NDA before seeing your deck.
Equally, you do not always need one. If the information is not really secret, if there is already a contract covering confidentiality (many employment and services agreements include confidentiality clauses), or if asking for one would derail a low-stakes conversation, an NDA can be more friction than protection. Judge it by the sensitivity of what you are about to reveal.
What an NDA can and cannot do
This is where founders most often go wrong, so it is worth being blunt.
An NDA controls confidentiality. It does not transfer intellectual property. If you share an idea under an NDA and the other side builds on it, the NDA governs whether they were allowed to disclose or misuse your confidential information; it does not, by itself, hand you ownership of anything they create. Under the Copyright, Designs and Patents Act 1988, copyright in a work first belongs to its author (or, for works made in the course of employment, to the employer), and that ownership is not altered by an NDA. If you need someone's work product to belong to you, that is a job for an IP assignment, not a confidentiality clause smuggled into an NDA.
An NDA is only as strong as its drafting. Vague definitions of confidential information, missing exceptions, or an unreasonable duration can weaken or invalidate it. This is the real risk with random free downloads of unknown origin, which is why we compare sources in the best NDA template sources UK guide.
An NDA does not prevent disclosure; it deters and remedies it. It cannot physically stop someone talking. What it does is create a legal obligation and a route to a remedy if they breach it. Practical control (who you let see the information, and how) matters alongside the paperwork.
An NDA needs the ordinary ingredients of a contract to bite, and its terms must be clear enough to enforce. A well-drafted England and Wales NDA names its purpose, its parties, its duration and its exceptions plainly.
Keeping the document to its actual job, protecting confidential information for a defined purpose and period, is what makes it hold up.
How 99 Data Rooms handles this
99 Data Rooms lets you go from "I need an NDA" to a signed, tracked document without switching tools. The AI Legal Drafting feature assembles your NDA from a library of vetted England and Wales clauses. The important point about how it works is what it does not do: it does not write legal wording from scratch or let a language model invent clauses. It selects and arranges reviewed clauses by ID based on your answers, so you get a current baseline fast, not machine-generated law. Both the mutual and one-way NDAs sit in the vetted template library, and either is a few plain questions away.
Because drafting lives in the same platform as sharing and signing, the NDA you assemble flows straight on. You can gate the document behind a verified email and a one-time code, share it as a tracked, revocable link inside a virtual data room, watch page-by-page analytics as the other side reads, and send it for e-signature (available from the Pro tier) with an audit certificate recording who signed, when, their intent and a SHA-256 fingerprint. Everything is UK-hosted in London with a 24-month audit trail. The draft is yours to keep even on the free tier. Because it is a starting point rather than finished legal advice, anything with real money or risk attached is worth a human review before you rely on it. The wider platform is in beta and improving fast; the drafter is live.
Draft your NDA for free
You can draft an NDA from vetted England and Wales clauses, keep it, then gate, track and sign it inside 99 Data Rooms. The free tier is a real tier, not a trial: three rooms, twenty-five active links, forever, no card required. Start for free, draft the NDA you need, and move up only when you want unlimited links, NDA gating, watermarking or in-browser signing.
Sources
- Copyright first ownership (an NDA does not transfer IP; copyright first belongs to the author, or the employer for employee works): Copyright, Designs and Patents Act 1988, s.11, https://www.legislation.gov.uk/ukpga/1988/48/section/11
Is an NDA legally binding in England and Wales?
Yes, generally. An NDA is a contract and is binding provided it has the usual ingredients of a contract and its terms are clear enough to enforce. Courts routinely uphold well-drafted confidentiality agreements. The weak point is rarely the concept and almost always the drafting, which is why a vetted template beats a random download. This is general information, not legal advice.
Does an NDA transfer intellectual property to me?
No. An NDA protects confidential information; it does not, on its own, transfer or assign intellectual property. Under the Copyright, Designs and Patents Act 1988, copyright first belongs to the author or, for employee works, the employer. If you need ownership of someone's work, use an IP assignment instead.
One-way or mutual: which NDA do I need?
Match it to the flow of information. If only you are disclosing, a one-way NDA fits. If both sides will share confidential material, use a mutual NDA. Presenting a one-way NDA to someone who is also disclosing tends to feel unfair and slows things down.
How long should an NDA last?
There is no single correct figure. Many commercial NDAs run one to three years, with confidentiality sometimes surviving longer for genuinely sensitive information. What matters is that the term is stated clearly and is reasonable for the kind of information involved.
Can I get an NDA for free?
Yes. You can draft an NDA from vetted England and Wales clauses on the 99 Data Rooms free tier and keep the draft. Our free NDA template for England & Wales guide explains the options and the difference between a vetted document and an anonymous download.