The “common interest” doctrine (sometimes called the “joint defense” doctrine) can extend the attorney-client privilege protection to communications among jointly represented clients—essentially negating what would be a waiver caused by sharing privileged communications outside the attorney-client relationship. However, lawyers should not see the common interest doctrine as a broad cure-all automatically allowing them to share privileged communications outside very narrow circumstances.
Two recent cases have emphasized that the common interest doctrine applies only in the case of litigation or potential litigation, and not at a time when the parties have “a mere awareness that one’s questionable conduct might some day result in litigation.” In re Santa Fe Int’l Corp. 272 F. 3d. 705, 711 (5th 2001); In re Grand Jury Subpoena, 274 F.3d 563, 575 (1st 2001) (rejecting the applicability of the common interest doctrine at a time when “no particular litigation or investigation was in prospect”).
Lawyers should not overestimate the availability of the common interest doctrine, and should be sure to document what the Santa Fe court held was the required—a “palpable threat of litigation at the time of the communication.” 272 F.3d at 711.