Indiana Code Title 2. General Assembly § 2-7-2-5

Sec. 5. If a material change occurs in any of the information contained in a registration statement, an appropriate amendment shall be filed within fifteen (15) days after the change.  Each registered lobbyist may file a notice of termination within fifteen (15) days after he ceases the activity which required his registration;  however, this does not relieve him of the reporting requirements of IC 2-7-3.