Confidentiality

Confidentiality refers to a set of rules or a promise—often formalized through confidentiality agreements—that restricts who can access certain information or how that information can be shared.

In the legal field, lawyers are generally required by law to keep all matters related to a client’s representation confidential. This duty is broader than the attorney–client privilege, which only protects direct communications between them. Both rules exist to encourage clients to be open with their lawyers, allowing for a vigorous defense. Without this protection, a client might hide a seemingly damaging fact that a skilled lawyer could use to their advantage, or the opposing side could spring a surprise in court. However, most jurisdictions allow lawyers to break confidentiality if they believe a client is about to kill or seriously harm someone, cause major financial or property damage, or use the lawyer’s services to commit a crime or fraud. In these cases, disclosure is usually discretionary, not mandatory. A few states, like New Jersey and Virginia, have made such disclosure mandatory. Some jurisdictions also require the lawyer to first try persuading the client to follow the law before revealing anything. These exceptions generally do not cover past crimes, even extreme ones like murder. Courts have upheld a lawyer’s right to remain silent in such situations, arguing that otherwise no criminal defendant could get a zealous defense. California is known for having one of the strongest confidentiality duties; until a 2004 amendment, its lawyers could not even disclose that a client was about to commit murder. Recent UK laws have also limited confidentiality for professionals like accountants, who must now report suspicions of fraud or even legitimate tax-saving schemes if unknown to tax authorities.

In English law, a breach of confidence requires three elements, as set out in the 1968 case *Coco v A N Clark (Engineers) Ltd*: the information must have a “quality of confidence,” it must have been shared in circumstances that create an obligation of confidence, and there must be an unauthorized use that harms the person who shared it. An 1896 case involving a doctor, William Smoult Playfair, highlighted the gap between lay and medical views on confidentiality. He learned that a patient had been pregnant while separated from her husband and told his wife, a relative, to protect her from “moral contagion.” The patient sued, and the doctor faced huge damages.

Medical confidentiality, which protects conversations between doctors and patients, dates back at least to the Hippocratic Oath, which says that whatever a physician sees or hears in a patient’s life that should not be spoken of abroad must be kept secret. Traditionally, medical ethics has treated this duty as nearly non-negotiable. In the United States, HIPAA’s Privacy Rule and various state laws enforce confidentiality, though many exceptions exist. For instance, many states require doctors to report gunshot wounds to police or impaired drivers to the Department of Motor Vehicles. Confidentiality is also challenged when a patient with a sexually transmitted disease refuses to tell a spouse, or in cases involving termination of pregnancy.