What is a transaction in which authority is conferred on another party called?

A transaction in which authority is conferred on another party is known as a mandate. In legal terminology, a mandate occurs when one person, the mandator, gives another person, the mandatary, the authority to act on their behalf in a specified matter. This type of agreement is often used in various contexts, including in notarial practices, where a notary may be required to act upon the instructions of another individual.

In contrast, commission generally refers to the act of performing a task or duty, typically associated with earning a fee or payment for services rendered, but it does not specifically denote the transfer of authority. Assignment typically involves transferring rights or property from one party to another rather than conferring authority to act on behalf of someone else. Delegation, while it implies giving authority, often pertains to the act of assigning responsibility within a certain task or project rather than a comprehensive transfer of authority over a transaction or situation.