Ultra vires is a Latin phrase that literally means "beyond the power." It is used as legal jargon in a number of contexts:

• In corporate law, ultra vires describes acts attempted by a corporation that are beyond the scope of powers granted by the corporation's charter, the laws authorizing its formation, or similar founding documents. Acts attempted by a corporation that are beyond the scope of is charter are void or voidable . Except in the case of non-profit corporations, this legal doctrine is obsolescent; within recent years, almost all business corporations are chartered to allow them to transact any lawful business. The doctrine may still have some life among non-profit corporations or state-created corporate bodies established for a specific public purpose, like universities. In some jurisdictions, such as Australia, legislation provides that a corporation has all the powers of a natural person plus others; also, the validity of acts which are made ultra vires is preserved.
• In municipal law , ultra vires describes attempts at local legislation that go beyond the powers granted to those bodies. Within the federal system of the United States, municipal bodies are created by the several states, and have only those powers to legislate on local matters that are conferred by the state legislature; attempts by local governments to exceed those grants are ultra vires.
• In British constitutional law, ultra vires describes patents, ordinances and the like enacted under the prerogative powers of the Crown that contradict statutes enacted by the King-in-Parliament. Almost unheard of in modern times, ultra vires acts by the Crown or its servants were previously a major threat to the rule of law.
• In administrative law, an act may be judicially reviewable ultra vires in a narrow or broad sense. Narrow ultra vires applies if an administrator did not have the substantive power to make a decision or it was wrought with procedural defects. Broad ultra vires applies if there is an abuse of power (e.g. Wednesbury unreasonableness or bad faith) or a failure to exercise an administrative discretion (e.g. acting at the behest of another or unlawfully applying a government policy). Either doctrine may entitle a claimant to various prerogative writs, equitable remedies or statutory orders if they are satisfied.