‘‘... a man must be able to consult his lawyer in confidence, since otherwise he might hold back half the truth. The client must be sure that what he tells his lawyer in confidence will never be revealed without his consent. Legal professional privilege is thus much more than an ordinary rule of evidence ... It is a fundamental condition on which the administration of justice as a whole rests ...’ (R v Derby Magistrates, ex p B  1 AC 487).
Legal advice privilege under English law protects written or oral confidential communications between a lawyer and a client for the purpose of giving or receiving legal advice, as well as documents which reflect such a communication.
Similarly, the attorney-client privilege under US law generally protects communications between in-house or external counsel and their clients that are intended to be confidential and made for the purpose of seeking or obtaining legal assistance or advice.
Requirement for a lawyer?
Under English law, there must be a ‘lawyer’ on the communication for legal advice privilege to apply. While this is defined widely to include solicitors, barristers, and foreign lawyers admitted to practice in their home jurisdiction, ‘lawyer’ does not extend to other professionals, such as accountants, even where they are purporting to provide legal advice, or to a non-legally-qualified compliance officer or investigations function – whether internal or external. Although English law does not draw any distinction between in-house lawyers and lawyers in private practice, the European Court of Justice has held that communications between a company and its in-house lawyers in the context of EU competition investigations are not protected by legal advice privilege on the basis that, unlike external lawyers, in-house lawyers are not deemed sufficiently independent.
The definition of lawyer for the purposes of attorney-client privilege under US law is also defined widely. In contrast to the English law position, attorney-client privilege can also protect communications with non-legal advisers if the purpose of the communication is to facilitate the rendering of legal service by the attorney. For example, communications and materials created during an investigation have been found to be privileged even if they are the result of interviews by non-attorneys so long as the non-attorneys are serving as ‘agents’ of the attorneys in the investigation.
Who is the client?
Under English law, only communications between a lawyer and a ‘client’ will be protected by legal advice privilege, and the frequently-posed question of ‘who is the client?’ for these purposes continues to cause unease. Not all communications that the lawyer has with employees at the corporate client will be privileged. Instead, ‘client’ is narrowly construed under English law to refer only to those individuals who, as a matter of fact, are authorised to give instructions to and receive advice from the lawyer in relation to the issue at hand. Who is the ‘client’ should be kept under review given that the individuals at the corporate client dealing with the lawyers will change over time.
In the United States, an employee is usually considered part of the corporate client group as long as four conditions are met:
- the communication is authorised by company superiors;
- the employee was aware that the communication related to legal advice;
- the communication concerns information that cannot be obtained from more senior employees; and
- the communication relates to the employee’s duties.
Communications between lawyers and employees who are not part of the corporate client group may be privileged under English and US law where litigation privilege or the work product doctrine applies – i.e. where the communication or document was prepared in anticipation of actual or contemplated litigation (see below).
"The purpose of the attorney-client privilege is ‘to encourage full and frank communication between attorneys and their clients and thereby promote broader public interests in the observance of law and administration of justice.’ ".(Upjohn Co. v United States, 449 US 383, 389 (1981))
What is a communication?
For legal advice privilege to apply under English law, there must be a communication between a lawyer and a client, or a document that reflects such a communication. This means that any preparatory material of the client that is not communicated to the lawyer may not be privileged under legal advice privilege principles.
By contrast, a lawyer’s preparatory material is privileged; the general rule is that if a lawyer commits to paper, during the course of his retainer, matters that he knows only as a consequence of the professional relationship with his client, those papers will be privileged even if they are not sent to the client.
Similar to English law, US law requires a communication to trigger the attorney-client privilege. The communication can be written or oral and can be to or from a lawyer. While US law protects the communication as long as it is for the purpose of seeking or obtaining legal advice, underlying facts that form part of the communication are generally not protected by the privilege unless they are themselves privileged. Likewise, documents transmitted to a lawyer are not shielded by privilege solely because they were communicated to a lawyer.
What is legal advice?
Legal advice privilege under English law arises in the context of giving or receiving legal advice. This is construed widely to cover advice given in a ‘relevant legal context’, including presentational advice on how to present a case to an inquiry, but may not cover situations where the lawyer is acting as general business adviser and advising on, for example, investment or finance policy or other business matters.
In the recent English case of Property Alliance Group Limited and The Royal Bank of Scotland plc  EWHC 3187 (Ch), the High Court upheld a claim to privilege by RBS in respect of certain factual updates and minutes prepared by Clifford Chance in the context of LIBOR investigations by regulators in various jurisdictions, given that they were part of the ‘continuum’ of communications between lawyer and client in a ‘relevant legal context’ – which in this case was to provide ‘advice and assistance’ in relation to the serious and complex matter of how to deal with and coordinate communications and responses to various regulators whose investigations had potentially serious consequences in terms of penalties and private action.
In the US case In re Kellogg Brown & Root, 756 F.3d 754 (D.C. Cir. 2014), the D.C. Circuit Court held that communications and materials created during a company’s confidential internal investigation are protected by the attorney-client privilege when ‘one of the significant purposes’ of the investigation is to obtain legal advice.