In the practice of law, judicial estoppel (also known as estoppel by inconsistent positions) is an estoppel which precludes a party from taking a position in a case which is contrary to a position they have taken in earlier legal proceedings. Although, in the United States, it is only a part of common law and therefore not sharply defined, it is generally agreed that it can only be cited if the party in question successfully maintained its position in the earlier proceedings and benefited from it.
Judicial estoppel is a doctrine which may be applied in matters involving closed bankruptcies wherein the former debtor attempts to lay claim to an asset which was not disclosed on the bankruptcy schedules.
In an early US articulation of the doctrine, the United States Supreme Court, in First National Bank Of Jacksboro v. Lasater, 196 U.S. 115 (1905), held at 119:
See also Sierra Switchboard Co. v. Westinghouse Electric Corp., 789 F.2d 705 (9th Cir. 1986).