tender back rule

Definition from Nolo’s Plain-English Law Dictionary

A legal principle requiring a party who seeks to invalidate a contract to return whatever that party received under the contract's terms. For example, a former employee who receives a severance package in exchange for agreeing not to sue a former employer for wrongful termination must tender back the money if he or she decides to sue and claim that the release is invalid. There is an exception to the tender back rule for age discrimination claims brought under the Age Discrimination in Employment Act: Those suing for age discrimination despite having signed a release do not have to tender back the money they received for signing (although they may have to reimburse the employer for that money if they win the lawsuit).

Definition provided by Nolo’s Plain-English Law Dictionary.