Every motor vehicle factory representative or distributor representative shall have his license upon his person when engaged in his business, and shall display the same upon request. The name of the employer of such factory representative or distributor representative shall be stated on said license. In case of a change of employer, the holder of such license shall immediately mail same to the commission for its endorsement of such change thereon. A fee of two dollars and fifty cents ($2.50) shall be charged by the commission for endorsing each such change of employer on said licenses, and said fee shall accompany the application for change.