It is common for the parties to a commercial transaction or relationship to conclude that their circumstance requires more than a nondisclosure agreement. And it is frequently the case that certain privileged attorney-client communications may need to be shared. The parties often seek to protect that information with what are known as common-interest agreements or joint defense agreements, depending on the circumstances. Both of the agreements fall under a broad legal umbrella known as the “common interest doctrine” (doctrine). While the doctrine is generally known, it is often misunderstood. Confidential attorney-client communications can be privileged and withheld from discovery unless they lose confidentiality by being disclosed to a third party.

The doctrine permits the sharing of a qualified privileged communication to another provided that the parties are separately represented and have a common legal, factual or strategic interest for exchanging the information and it is exchanged with each other and their respective lawyers, Restatement (Third) of Law Governing Lawyers Section 76 (2000). Essentially, the doctrine requires protectable information, substantially identical interest in sharing information, and the parties are represented by counsel.