Department of Revenue issued the following announcement on Sept. 27
Effective October 3, 2021, the Illinois Secretary of State’s (SOS) motor vehicle unit at its Chicago South facility (9901 S. Martin Luther King Dr., Chicago, IL) will be closed approximately four weeks for renovations. During this closure, individuals needing to submit sales tax returns or make in-person sales payments for motor vehicles, boats, and trailers may visit an alternate SOS facility or Illinois Department of Revenue office. Locations in closest proximity to SOS Chicago South are: James R. Thompson Center (100 W. Randolph St., Chicago, IL), SOS North facility (5401 N. Elston Ave., Chicago, IL), and SOS West facility (5301 W. Lexington St., Chicago, IL).
Original source can be found here.