205 ILCS 620/4-3
Any foreign corporation acting in this State in a fiduciary capacity pursuant to the provisions of Article IV and Article IVA of this Act shall be deemed to have appointed the Secretary of State to be its true and lawful attorney upon whom may be served all legal process in any action or proceeding against it relating to or growing out of any trust, estate or matter in respect of which such foreign corporation has acted or is acting in this state in any such fiduciary capacity, and the acceptance of or engagement in this State in any acts in any such fiduciary capacity shall be signification of its agreement that any such process against it which is so served, shall be of the same legal force and validity as though served upon it personally. Service of such process shall be made by delivering to the Secretary of State, the corporation department of the office a copy of such process, together with the fee for service of process required by the Secretary of State, and such service shall be sufficient service upon said foreign corporation if notice of such service and a copy of the process are, within 10 days thereafter, sent by registered mail by the plaintiff to the defendant at its principal office in such other state or territory and the plaintiff's affidavit of compliance herewith is appended to the summons. The court in which the action is pending may order such continuances as may be necessary to afford the defendant reasonable opportunity to defend the action. The fee paid by the plaintiff to the Secretary of State at the time of the service may be recovered as taxable costs by the plaintiff if such party prevails in the action. The Secretary of State shall keep a record of all process served upon him under this section and shall record therein the time of such service.
205 ILCS 620/4-3