Delegata potestas non potest delegari is a Latin phrase which states that “no delegated powers can be further delegated.” It is also known as delegatus non potest delegare which means “one to whom power is delegated cannot himself further delegate that power.” One who has the power or authority from another to do an act must do it himself/herself as this is a trust or confidence reposed in that person personally. It cannot be assigned to stranger whose ability and intergrity might not be known to the principal. The U.S. and the U.K. jurisdictions follow this principle.
The principle was first articulated in Canada in the year 1943 in the Canadian Bar Review. Delegata potestas non potest delegari was first cited by the Supreme Court of the United States in United States v. Sav. Bank, 104 U.S. 728 (1881). In this case, it was argued that the duty imposed by statute on the commissioner cannot be delegated to a collector. Delegata potestas non potest delegari is also mentioned in the catholic canon law, title XIII.