Definition of ultra vires in English:

ultra vires

Pronunciation /ˌəltrə ˈvīrēz/ /ˌəltrə ˈvaɪriz/


  • Acting or done beyond one's legal power or authority.

    ‘at one point they argue that the legislation is ultras vires’
    • ‘As a result, a taxpayer who has made a payment pursuant to ultra vires legislation has a right to restitution.’
    • ‘It is not suggested that Byelaw 20 was itself ultra vires the powers which the primary legislation conferred upon the British Railways Board.’
    • ‘An ultra vires act is one beyond the purposes or powers of a corporation.’
    • ‘This lesson provides an overview of the historical significance of the ultra vires doctrine, its subsequent decline in importance, and its modern status.’
    • ‘Delegated legislation is also subject to control by the courts whose judges can declare a piece of delegated legislation to be ultra vires.’


  • Beyond one's legal power or authority.

    • ‘he will take action against any body acting ultra vires’


Latin, literally ‘beyond the powers’.