During the administrative authority proceedings, the client may act in person or through his legal representative, as well as through a person authorized by him or his legal representative.

If the client does not act in person, the authority will examine the person's right to be represented. The proxy must prove the right of representation. The authorization must be recorded in writing (in an authentic instrument or in a private document of full probative value) or recorded in the minutes. In the case of a written authorization, the proxy must attach his original authorization or a certified copy thereof to the documents at the time of the first contact.