Attorney–client privilege or lawyer–client privilege is the common law doctrine of legal professional privilege in the United States. Attorney–client privilege is "[a] client's right to refuse to disclose and to prevent any other person from disclosing confidential communications between the client and the attorney."
The attorney–client privilege is one of the oldest privileges for confidential communications. The United States Supreme Court has stated that by assuring confidentiality, the privilege encourages clients to make "full and frank" disclosures to their attorneys, who are then better able to provide candid advice and effective representation.
General requirements under United States law
Although there are minor variations, the elements necessary to establish the attorney–client privilege generally are:
The asserted holder of the privilege is (or sought to become) a client; and
The person to whom the communication was made: is a member of the bar of a court, or a subordinate of such a member, and in connection with this communication, is acting as an attorney; and The communication was for the purpose of securing legal advice.
There are a number of exceptions to the privilege in most jurisdictions, chief among them: the communication was made in the presence of individuals who were neither attorney nor client, or was disclosed to such individuals, the communication was made for the purpose of committing a crime or tort, the client has waived the privilege (for example by publicly disclosing the communication).
A corollary to the attorney–client privilege is the joint defense privilege, which is also called the common interest rule. The common interest rule "serves to protect the confidentiality of communications passing from one party to another party where a joint defense or strategy has been decided upon and undertaken by the parties and their respective counsel."
An attorney speaking publicly in regard to a client's personal business and private affairs can be reprimanded by the bar or disbarred, regardless of the fact that he or she may be no longer representing the client. Discussing a client's or past client's criminal history, or otherwise, is viewed as a breach of confidentiality.
The attorney–client privilege is separate from and should not be confused with the work-product doctrine.
When the privilege may not apply
When an attorney is not acting primarily as an attorney but, for instance, as a business advisor, member of the Board of Directors, or in another non-legal role, then the privilege generally does not apply.
The privilege protects the confidential communication, and not the underlying information. For instance, if a client has previously disclosed confidential information to a third party who is not an attorney, and then gives the same information to an attorney, the attorney–client privilege will still protect the communication to the attorney, but will not protect the communication with the third party.
The privilege may be waived if the confidential communications are disclosed to third parties.
Other limits to the privilege may apply depending on the situation being adjudicated.
Crime–fraud exception
The crime–fraud exception can render the privilege moot when communications between an attorney and client are themselves used to further a crime, tort, or fraud. In Clark v. United States, the U.S. Supreme Court stated that "A client who consults an attorney for advice that will serve him in the commission of a fraud will have no help from the law. He must let the truth be told." The crime–fraud exception also does require that the crime or fraud discussed between client and attorney be carried out to be triggered. U.S. courts have not yet conclusively ruled how little knowledge an attorney can have of the underlying crime or fraud before the privilege detaches and the attorney's communications or requisite testimony become admissible.
Disclosure ostensibly to support lawyer's own interests
Lawyers may disclose confidential information relating to the retainer where they are reasonably seeking to collect payment for services rendered. This is justified on policy grounds. If lawyers were unable to disclose such information, many would undertake legal work only where payment is made in advance. This would arguably adversely affect the public's access to justice.