Assignatus utitur jure auctoris – is a Latin phrase, meaning “That which is assigned takes with it for its use the rights of the assignor” or “an assignee is clothed with the rights of their principal”. It is a maxim which governs principal–agent relationships.
This means that where assignatus utitur jure auctoris applies, the assignee possesses all the rights of the person that they represent, however the value of subject matter that is assigned is limited to a sum that is equal to or less than the value of the subject matter.
In other words, one cannot assign, or have the same rights of their principal in the case of an assignment, if the purported assignment of property is greater than the value of what it is worth. A person cannot assign what they do not have. Once the rights have been assigned a person becomes entitled to the rights and to the actions at law by which that right may be enforced.