Latin for without authority or, literally, beyond powers.
A decision which is beyond the powers or authority of the person or organization which took it.
In Davis v. Reed, these words of Justice Daughtery of the United States District Court:
"(U)ltra vires acts ... are acts beyond the official's statutory authority, acts taken pursuant to constitutionally void powers, or acts exercised in a constitutionally void manner."
Similarly, these words of Justice Schneider of the United States Bankruptcy Court in Re John E. Keim, Debtor:
"An act of a governmental agency is ultra vires if it is beyond the express or implied powers conferred by statute."
When a decision is thought to be ultra vires, the typical remedy is to get a higher level judicial body, such as a Court, to assess and rule on it.
If the decision has already been made, the remedy is certiorari. If the decision is anticipated, the remedy is prohibition.
In the context of a company:
"... contracts which are void because in excess of corporate power (are) ultra vires...."1
In Rolled Steel v British Steel, Justice Browne-Wilkinson wrote of ultra vires:
"Because the literal translation of the words is beyond the powers, there are many cases in which the words have been applied to transactions which, although within the capacity of the company, are carried out otherwise than through the correct exercise of the powers of the company by its officers.... In my judgment, the use of the phrase ultra vires should be restricted to those cases where the transaction is beyond the capacity of the company and therefore wholly void."