A non-disclosure agreement (NDA), often called a confidentiality agreement, is a contract used to protect confidential information disclosed for a defined purpose (for example, M&A due diligence, outsourcing, R&D, employment or settlement talks). The term is descriptive rather than statutory; enforceability rests on contract principles and the equitable/common-law duty of confidence, with broadly consistent approach across England & Wales, Scotland, Northern Ireland and Ireland. UK Trade Secrets (Enforcement, etc.) Regulations 2018 and Ireland’s European Union (Protection of Trade Secrets) Regulations 2018 provide additional remedies for trade secrets.Key features typically include:- Clear definition of “Confidential Information” and the permitted purpose.- Permitted recipients and safeguards; need-to-know and security measures.- Carve-outs (public domain, independently developed, already known, legally required disclosure).- Duration (finite for ordinary information; potentially indefinite for trade secrets).- Return/destruction, no-licence, and no-warranty clauses.- Governing law and jurisdiction.- Remedies: damages and urgent injunctive relief (interim injunction; interdict in Scotland; interlocutory injunction in Ireland), delivery up and account of profits.NDAs cannot lawfully prevent protected disclosures or reporting to regulators/law enforcement (e.g., UK whistleblowing law and Ireland’s Protected Disclosures regime). Overbreadth, ambiguity or unreasonable restraints risk unenforceability. Mutual and one‑way forms are common; choice depends on whether both parties disclose.