A real person and a legal person have the same rights and duties and have the same Competency. Their difference is exceptional. The exception mentioned in the law is the inherent rights and duties of humans. However, there are examples such as right of pre- emption and executorship, which is a source of dispute due to the existence of companies' competence, and it is not possible to express an opinion whether it is specific to a natural person or a legal entity. Considering that these two legal institutions are related to the Competency, so this article first examines the Competency of the companies, then the position of these two legal institutions in relation to the companies. Since the comparative study between legal systems leads to a better understanding of their strengths and weaknesses, the present article, with a descriptive, comparative analytical method and in a library method, examines and adapted the works of commercial companies' Competency according to the commercial law of Iran, Egypt and Lebanon. Finally, according to the commercial law articles of these countries, it was concluded that commercial companies have the authority to accept probate in the law of Iran, Egypt and Lebanon, although it must be accepted by a representative from the company. Regarding the right of pre- emption, since the commercial law of Egypt and Lebanon is derived from the French commercial law on the one hand, and on the other hand, it is based on Sunni jurisprudence, and the conditions for the creation of the right of pre- emption are different between Sunnis and Shiites, they do not grant the right of pre- emption to companies. But partners are given such a right.