Indiana Code Title 23. Business and Other Associations § 23-0.5-4-10

Sec. 10. (a) A represented entity may be served with any process, notice, or demand required or permitted by law by serving its registered agent.

(b) If a represented entity ceases to have a registered agent, or if its registered agent cannot with reasonable diligence be served, the entity may be served by registered or certified mail, return receipt requested, or by similar commercial delivery service, addressed to the entity at the entity's principal office.  The address of the principal office of a domestic filing entity or registered foreign entity must be as shown in the entity's most recent biennial report filed by the secretary of state.  Service is effective under this subsection on the earliest of:

(c) If process, notice, or demand cannot be served on an entity under subsection (a) or (b), service may be made by handing a copy to the individual in charge of any regular place of business or activity of the entity if the individual served is not a plaintiff in the action.

(d) Service of process, notice, or demand on a registered agent must be in a written record, but service may be made on a commercial registered agent in other forms, and subject to such requirements, as the agent has stated in its listing under section 4 of this chapter that it will accept.

(e) Service of process, notice, or demand may be made by other means under law other than this article.