The common interest doctrine can sometimes protect as privileged communications among separately represented clients who share a sufficiently common legal interest. Courts take varying approaches to this important doctrine.
The key difference among courts is whether the doctrine can apply to those who are not in or are anticipating litigation. In Fond Du Lac Band of Lake Superior Chippewa v. Cummins, Case No. 22-CV-0170 (PJS/LIB), 2025 U.S. Dist. LEXIS 151768 (D. Minn. Aug. 7, 2025), the U.S District Court for the District of Minnesota assessed the doctrine’s applicability to communications about a land conveyance. Explaining that the doctrine can apply “in a litigated or non-litigated matter,” the court found the doctrine inapplicable based on the nature of the interests rather than on the transactional nature of the setting. Id. at *6-9. Four days later, in Pentacon BV v. Vanderhaegen, the U.S. District Court for the Southern District of New York repeatedly emphasized that the doctrine can only apply when participants are in “pending or contemplated litigation” — quoting a New York state court’s holding that the doctrine “protects only documents prepared in anticipation of litigation.” No. 23 Civ. 2172 (KPF), 2025 U.S. Dist. LEXIS 155898, at *13 (S.D.N.Y. Aug. 11, 2025) (citation omitted).
Lawyers considering the common interest doctrine’s applicability should remember this potentially dispositive difference between courts’ approaches, keeping in mind that the majority takes the narrower view.
