In the complex realm of corporate litigation, the sanctity of attorney-client privilege is often the backbone of a robust defense strategy. Yet, the scope of this privilege can blur when multiple corporations collaborate with separate legal teams. In such situations, the common interest privilege (CIP) becomes a crucial tool, enabling corporations with distinct legal counsel to share information and strategize jointly without forfeiting confidentiality. This extension is vital in an era where legal alliances are essential for navigating complex legal disputes.

However, an examination across the U.S. Courts of Appeals reveals significant differing requirements to invoke CIP, making it crucial for corporations to understand these nuances to avoid the risk of their intended confidential communications being unexpectedly exposed in discovery.