Covenant Not to Sue Law and Legal Definition

A covenant not to sue is an agreement entered into by a person who has a legal claim against another but agrees not to pursue the claim. Such a covenant does not extinguish a cause of action and does not release other joint tort-feasors even if it does not specifically reserve rights against them.

For example, in environmental law, a covenant not to sue is a tool that allows redevelopment of contaminated properties without the risk of liability for historical contamination. A covenant not to sue is an assurance that once a site is cleaned up to current standards, the Commissioner will not require any additional cleanup in the future.