Ill. Admin. Code tit. 92, § 1065.35
a) Each ESDS must maintain an established place of business that:
4) includes an office facility, subject to the following conditions:
b) An ESDS that has a licensed established place of business may operate a branch office provided all the requirements of the established place of business are met and the branch office bears the same name and is operated as a part of the same business entity as the established place of business.
1) owned or leased by the ESDS;