Breach of confidence CASES

In English law, breach of confidence protects confidential information against unauthorised use or disclosure. The duty can arise by contract (for example, an Non Disclosure Agreement) or in equity wherever information is imparted or obtained in circumstances importing an obligation of confidence. The aim is to uphold trust, protect legitimate secrecy and prevent unfair use, while allowing disclosure where the public interest requires it.

Definition and principles

At its core, the action asks three questions. First, does the information have the necessary quality of confidence (it is not trivial or generally accessible)? Secondly, was it disclosed or obtained in circumstances importing an obligation of confidence (for example, an express NDA, a professional or employment relationship, or notice that the material is confidential)? Thirdly, has there been unauthorised use or disclosure to the detriment of the confider (which can be commercial, reputational or practical)? Equity will also restrain third parties who receive information with notice that it is confidential.

Scope and relationship to neighbouring areas

Commercial and technical information. Breach of confidence is frequently used to protect business plans, customer lists, pricing, algorithms and know-how. Trade secret legislation now provides a statutory route for qualifying information, but equitable confidence remains important, especially where the statutory definition is not met or parallel relief is needed.

Private information. Where the gist of the complaint is intrusion into personal life (health, relationships, images), the modern cause of action is misuse of private information. Nonetheless, older cases and some hybrid situations still use confidence language; cross-reference both tags for students.

Data protection. Statutory duties (for example, under UK GDPR) may run in parallel. Those regimes regulate processing; confidence controls disclosure and use as between confider and recipient.

Common contexts

• Employment and business transfers: departing employees taking client lists or technical materials; due-diligence disclosures limited to the deal purpose.
• Professional relationships: lawyers, doctors, banks and consultants handling clients’ confidential material.
• Collaborations and pitching: ideas or prototypes shared for a limited purpose; later use outside that purpose.
• Government and public bodies: sensitive operational or commercial information shared under assurances of confidence, subject to public-interest limits.

Defences and limits

There is no confidence in iniquity: equity will not protect information that reveals serious wrongdoing or dangers to the public. Information already in the public domain (in substance) will not remain protected, though narrow or specialist disclosure does not necessarily destroy confidence. Consent, waiver and acquiescence are complete answers. Where freedom of expression is engaged, courts balance confidentiality against the public interest in disclosure, using proportionate, evidence-based reasoning.

Remedies and procedure

The court can grant interim and final injunctions (including springboard relief to neutralise an unfair head start), delivery up or destruction of materials, imaging and preservation orders, and damages or an account of profits. Confidentiality clubs, sealing orders and anonymisation are used to protect sensitive material during litigation. Speed and evidence are critical: delay can defeat interim relief and uncontrolled disclosure can render final relief nugatory.

Practical importance

For claimants, define the confidential corpus precisely, show how confidentiality was created and communicated, and explain the limited purpose of any sharing. Keep a clear documentary trail (NDAs, access logs, lab books, version histories). For defendants, scrutinise whether the information was truly secret, whether any obligations were limited in scope or duration, and whether the alleged use falls within a permitted purpose. Consider whether narrow undertakings and protocol-level safeguards can resolve disputes proportionately.

See also: Misuse of private information; Trade secrets; Non-disclosure agreements; Data protection; Passing off; Fiduciary duty; Public interest; Interim injunctions.