Confidentiality and privilege 

Students often treat confidentiality and legal professional privilege as if they were the same idea, but they answer different questions. Confidentiality is the broad ethical duty a lawyer owes not to disclose information about a client's affairs. Privilege is a narrower rule of evidence about whether a particular communication can be compelled to be produced or given in evidence, whether in court or in some other compulsory process. Almost everything that is privileged is also confidential, but a great deal of confidential information is not privileged at all.

The duty of confidentiality

The ethical duty of confidentiality is deliberately broad. It generally covers all information a lawyer becomes aware of in the course of, and for the purpose of, the client relationship, regardless of its source, and regardless of whether it would ever be relevant in litigation. It applies whether the information came from the client directly, from a third party, or from the lawyer's own observations while acting for the client. The duty does not depend on the information being especially sensitive or damaging — the starting position is that client information is simply not to be disclosed, subject to defined exceptions. It also generally continues after the retainer ends and, in substance, survives the client's death.

Privilege as a narrower rule

Legal professional privilege (sometimes called client legal privilege) is a rule of evidence law that protects certain confidential communications — principally, communications between a lawyer and client made for the dominant purpose of giving or obtaining legal advice, or for use in actual or contemplated litigation, the test confirmed in Esso Australia Resources Ltd v Commissioner of Taxation (1999) 201 CLR 49¹ — from being compelled to be disclosed to a court, a regulator, or another party. Privilege belongs to the client, not the lawyer, and the client can choose to waive it. Because privilege is narrower than confidentiality, a communication can be confidential without being privileged — for example, routine administrative correspondence about a matter, or information a lawyer learns about a client that has nothing to do with giving legal advice. In that situation, the ethical duty not to disclose the information may still apply even though privilege would not protect it from compulsion if the question of production ever arose.

Why the distinction matters in practice

Getting the distinction right matters because the two concepts can point in different directions. A lawyer might be professionally required to keep information confidential as between the lawyer and the rest of the world, while privilege determines a separate and narrower question: whether that same information could lawfully be withheld if a court or other body sought to compel its production. Conflating the two can lead a student, or a practitioner, to assume information is protected from compulsion simply because it is confidential, which is not a safe assumption.

Exceptions to confidentiality

The duty of confidentiality is not absolute. Recognised exceptions generally include:

• Client consent — a client can authorise disclosure, and disclosure within the scope of that informed consent does not breach the duty.
• Preventing a serious and imminent risk to safety — where disclosure is necessary to prevent a serious risk to the life, health, or safety of a person, confidentiality may properly give way.
• Legal compulsion — where a specific legal obligation requires disclosure, such as a valid court order or a specific statutory reporting obligation, the lawyer may or must disclose accordingly, generally to the extent the compulsion actually requires and no further.

These exceptions are narrow and are not a general licence to disclose whenever a lawyer judges it convenient or even morally preferable; each rests on a specific, defined justification.

Statute has since closed the gap from the other direction. Section 131A of the Evidence Act 1995 (NSW) and its Victorian equivalent apply the Act's privilege provisions to disclosure requirements including pre-trial discovery, and in Expense Reduction Analysts Group Pty Ltd v Armstrong Strategic Management and Marketing Pty Ltd (2013) 250 CLR 303² the Court confirmed at [32] that the common law waiver considerations "apply with equal force" to that statutory question. Identify whether the uniform Act applies before choosing your test.

Privilege is not itself a basis for an injunction. In Glencore International AG v Commissioner of Taxation [2019] HCA 26³ a single joint judgment of seven Justices held that legal professional privilege is an immunity from compulsory disclosure and did not support an injunction restraining the Commissioner's use of privileged documents that had been stolen and disseminated; the plaintiffs had not sought relief on the ground of confidentiality. The Court said that, on the present state of the law, once privileged communications have been disclosed resort must be had to equity, where the juridical basis for relief is confidentiality ([34]). It also read Expense Reduction as a case about documents mistakenly disclosed in discovery, where the court's case management powers were enough, and not as allowing privilege to be asserted to obtain relief in the nature of an injunction ([36]). Whether equity would have granted relief on the ground of confidentiality was not decided.

Applying this in a problem question

1. Identify whether the question is really about confidentiality (can the lawyer disclose it at all) or privilege (can disclosure be compelled) — the two calls for analysis are different.
2. If the information came from or concerns the client and arose from the retainer, start from the position that it is confidential.
3. Ask separately whether the communication meets the narrower test for privilege, focusing on its dominant purpose.
4. If disclosure has occurred or is proposed, check it against the recognised exceptions — consent, serious and imminent risk to safety, or specific legal compulsion — rather than assuming disclosure is fine because it seems reasonable.
5. Where compulsion is in play, consider whether privilege has been, or could be, claimed, and who holds the right to waive it.