The doctrine is an exception to the rule that disclosure to third parties waives privilege. Where separately represented parties share a common legal interest, communications made in furtherance of that interest remain protected.
It is not an independent privilege; the communication must already be privileged before sharing.
Alternative Names:
Common Interest Privilege, Allied Party Doctrine
Why it Matters?
The doctrine enables coordinated defense among codefendants, insurers and insureds, and related corporate entities, which is essential in multi-party litigation. The recurring limitation is that a shared commercial interest is not enough in most jurisdictions, and the interest must be legal and generally identical rather than merely similar. Parties whose interests may later diverge should document the arrangement carefully.
Frequently Confused with
Related terms
Frequently asked questions
Is a shared business interest sufficient?
Does the doctrine create privilege?
