A non-disclosure agreement (NDA) protects your invention by making the person you share it with contractually obligated to keep it confidential — and, importantly, by preserving your invention's status as a trade secret and as unpublished for patent purposes. It is the right tool when talking to engineers, manufacturers, and contractors. It is usually the wrong ask when approaching investors and large companies, who routinely decline to sign. Knowing which situation you are in is most of the game. This article is educational information for inventors, not legal advice — for agreements with real money at stake, have an attorney review your specific situation.

What an NDA actually does — and does not do

An NDA gives you a contract claim if the other party discloses or misuses your confidential information. That matters in two ways. First, it creates a legal remedy against the specific person who signed. Second, disclosure under an NDA generally does not count as a public disclosure — which helps preserve your ability to file for patent protection and keeps trade-secret status intact.

What an NDA does not do: it does not stop an unrelated third party from independently inventing the same thing, it does not give you rights against anyone who never signed it, and it is not a substitute for patent protection. If someone lawfully learns of your idea elsewhere, the NDA is irrelevant. For what actually creates ownership rights in an invention, see the patents and intellectual property pillar — and for a famous myth about cheap protection, our piece on the poor man's patent.

Who will sign an NDA — and who will not

Will usually sign

  • Engineering and design firms. Signing NDAs is standard practice; a firm that hesitates is a red flag. (Projects House signs NDAs with clients as a matter of course.)
  • Manufacturers and suppliers. Routine, especially once you are requesting quotes with drawings attached.
  • Contractors and freelancers. Standard — ideally paired with an IP-assignment clause so work they create for you belongs to you.
  • Prospective co-founders and employees. Normal and expected.

Will usually refuse

  • Venture capital and angel investors. They see thousands of pitches, many overlapping, and signing NDAs would expose them to endless claims. Asking is widely read as a sign of inexperience.
  • Large companies reviewing outside ideas. Most have formal open-innovation policies that require submissions on their terms, not yours — a dynamic we cover in the selling your invention pillar.

When the other side will not sign, protect yourself differently: share the problem and the benefits, hold back the enabling details, and consider filing a provisional patent application first so you have a documented filing date before the meeting.

What a solid inventor NDA covers

  • Definition of confidential information — broad enough to cover drawings, prototypes, test data, and business plans, with standard carve-outs (publicly known, independently developed, lawfully received elsewhere).
  • Permitted use — the recipient may use the information only to evaluate or perform the work, nothing else.
  • Term — commonly two to five years for the agreement, with trade secrets often protected for as long as they remain secret.
  • No license granted — sharing information transfers no ownership.
  • Mutual vs one-way — a mutual NDA, where both sides' information is protected, is often easier to get signed and reads as more professional.

NDAs and your patent timeline

In the US, publicly disclosing your invention starts a one-year clock to file a patent application, and most other countries have no grace period at all. Disclosures made under a valid NDA are generally not public disclosures — which is exactly why careful inventors put one in place before showing a prototype to anyone outside the patent process. Before investing in filings, it is also worth running a patent search to see what protection is realistically available. First-time inventors can find the whole protection-and-development sequence laid out in the first-time inventor guide.

Develop your product with a partner that respects your IP

The practical reality is that you cannot develop a product alone under total secrecy — you will need engineers, prototypers, and manufacturers, and the professional way to work with them is under NDA with clear IP-assignment terms. Projects House works under NDA from the first conversation, and everything we design for a client belongs to the client. Reach out through the contact form to discuss your invention in confidence.