'Legal privilege' exists to protect confidential communications in order to seek advice from a lawyer. It can protect certain communications from disclosure, even from the Court, information requests or under subpoena. Privilege can be pierced by legislation (such as in a Royal Commission) or lost.

In Victoria, client legal privilege is defined in the 2008 Evidence Act from section 117.

In the context of legal proceedings, there are 3 main types of privilege, including: 

1. Legal Professional Privilege; 

2. Common Interest Privilege; and 

3. 'Without Prejudice' Privilege. 

Legal Professional Privilege (or, 'LPP') applies to communication (including both oral and written) that is confidential in nature and passes between a lawyer and their client, or between a lawyer, client and/or third party. Communication is said to be subject to Legal Professional Privilege if the communication is brought into existence for the dominant purpose of either: 

1. a lawyer giving legal advice to the client (aka Legal Advice Privilege); and/or 

2. the communication is used and/or relied upon in the context of litigation. (aka Litigation Privilege).

Privilege is held by the client, and is therefore the client's prerogative for the communication to remain privileged.

'Common Interest Privilege' (or, 'CIP') is privilege that applies to parties who have a shared or similar interest in the confidential communication. Practically speaking, Common Interest Privilege is often engaged, for example, in communications between Defendants and/or Third Parties that have been joined to the same proceeding.

Common Interest Privilege is not waived because of a disclosure to a person or persons who had, at the time of the disclosure, a common interest relating to actual or anticipated proceedings (see section 122 (5) (c)). 

'Without Prejudice' Privilege applies to those confidential communications that are exchanged in the context of settlement negotiations. In Victoria, the Evidence Act provides for protection of and "exclusion of evidence of settlement negotiations". This privileges communications made between parties in a dispute, including a third party, in connection with an attempt to negotiate a settlement of the dispute (see section 131 (1) (a)). 

In practice, this privilege enables parties to engage in negotiation or attempts to resolve or narrow the issues in dispute, without being concerned that the representations or concessions in those communications will be later relied on in actual or anticipated proceedings. 

This privilege can also be limited "save as to costs", as there may be costs consequences if parties act unreasonably or there is a dispute regarding the costs associated with a legal proceeding.

Legal Professional Privilege can be waived (or, lost), if you act in a way that is not consistent ensuring the communication remains confidential. Legal Professional Privilege can be waived by: 

1. intentional disclosure of the communication; 

2. unintentional disclosure of the communication; and/or 

3. implied waiver.

For example, if the substance of the advice is communicated to too many people or disclosed in a communication, this can be viewed as the privilege being waived and no longer confidential. Another common example is if the "dominant purpose" of the communication is not legal advice. 

Confidential communications and protected health information

Victoria has an additional exception to evidence being adduced in Court under the Evidence (Miscellaneous Provisions) Act 1958 (Vic) section 32C. This protects confidential communications by a person who alleges a sexual offence has been committed against them to their treating registered medical practitioner or counsellor.
There are exceptions to this protection and the scope is uncertain as there is little case law at this stage. 

Commonwealth Redress Scheme

The legislation for the Commonwealth Redress Scheme for people who have experienced child abuse in an institutional setting protects information about a person or institution which is provided to, or obtained by, the Scheme for the purpose of assessing an application for redress. The communications cannot be compelled to be produced to a Court.

What is 'Commercial in Confidence'?

The 'Commercial in Confidence' protects confidential information from disclosure and is predominantly used in the context of commercial agreements between interested parties. Central to this concept is clearly specifying what constitutes confidential information in the subject agreement to ensure all parties understand their obligation. Commercial in confidence headings, confidentiality clauses, and Non-Disclosure Agreements are common methods used to legally bind parties to confidentiality, and often serves to legally protect sensitive business information, although these can be challenged and may still require disclosure to the Court if relevant to the issues in dispute.