Ultra Vires
Ultra vires means beyond the powers. In Texas corporate law the concept is nearly dead: section 20.002 provides that lack of corporate capacity may not be the basis of any claim or defense, and acts beyond a corporation's stated purposes remain valid. In public law the term means something different and remains very much alive.
The phrase carries two meanings in Texas, and confusing them wastes a lot of briefing. In corporate law it describes an act outside the entity's powers, and the doctrine has been all but abolished. In suits against government officials it describes conduct outside an official's legal authority, and it is the main route around governmental immunity.
The corporate sense
Tex. Bus. Orgs. Code § 20.002(a) is blunt. Lack of capacity of a corporation may not be the basis of any claim or defense at law or in equity. Subsection (b) then validates the acts themselves, providing that an act of a corporation or a transfer of property is not invalid because the act was beyond the scope of the stated purposes of the corporation, or because it was inconsistent with a limitation on the authority of an officer or director to exercise a statutory power.
So a counterparty cannot escape a contract by discovering that a certificate of formation limited the company to some narrower business. That defense is gone. What remains is the enforcement mechanism in subsection (c), which preserves the unauthorized character of an act for three uses. A shareholder or member may sue the corporation to enjoin performance. The corporation may proceed against an officer or director who exceeded authority. The attorney general may act to enjoin the corporation or to terminate it.
Note the shape of that. The doctrine survives as an internal governance and regulatory tool, not as a shield for outsiders. A director who commits the company to a transaction beyond his authority may have personal exposure to the company even though the transaction binds it.
S.B. 29's codification of the business judgment rule intersects here, because the statutory presumption in favor of directors and officers can be rebutted by proof of conduct including ultra vires acts. The concept therefore retains real work inside fiduciary litigation even as it disappears from contract defenses.
The public law sense
Governmental immunity bars most suits against the state and its subdivisions. City of El Paso v. Heinrich, 284 S.W.3d 366 (Tex. 2009), holds that a claim that a government officer acted without legal authority, or failed to perform a purely ministerial act, is not barred, because such a suit does not attempt to control state action lawfully taken. The suit must be brought against the official in an official capacity rather than against the governmental entity, and the relief available is prospective. Retrospective monetary relief remains barred.
This matters to commercial parties more often than they expect. A company fighting a municipality, a utility district or a state agency over a permit, a contract award or a fee will frequently find that the only viable pleading is an ultra vires claim against a named official.
Getting the terminology right
If you are litigating in the Texas Business Court over an entity's internal affairs and you use the phrase, say which sense you mean. Opposing counsel will otherwise answer the argument you did not make, and the court will spend a hearing sorting it out. In corporate briefing the safer formulation is usually that the officer acted outside the authority conferred by the governing documents, which describes the conduct without invoking a doctrine that § 20.002 has largely retired.