| GPGrand Prairie Transit | Willow Springs | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| GIGroot Industries | Elk Grove Village | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| GRGroot Recycling & Services INC | Elk Grove Village | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| GIGrowmark INC | Albany | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| HQHahn Quarry | Galena | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| HKHalterman Kevin | Mazon | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| HSHamel Seed & Farm Supply INC | Worden | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| HPHanover Park Village of | Hanover Park | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| HMHanson Material Service Yd 46 | Algonquin | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| HFHarbor Foods | Winthrop Harbor | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| HOHathaway One Stop | Harrisburg | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| HMHeartland Memorial Center | Frankfort | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| HCHeaventree Candle CO | Wheeling | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| HPHeidner Property Management | Buffalo Grove | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| HFHeritage Fs-gibson City | Gibson City | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| HCHess Carl | Freeport | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| HSHickory Shores Resort | Carlyle | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| HSHighland Supply CORP | Highland | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| HTHohn's Tank Wash | Danville | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| HRHollenbaugh Residence | Loves Park | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| HSHolly Sorey | Fisher | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| HTHolthaus Truck Services INC | Beckemeyer | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| HTHp Tuners LLC | Buffalo Grove | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| HEHypermax Engineering | Gilberts | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| IIIcd Ironhorse INC | Monticello | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| IIIcon Identity Solutions | Elk Grove Village | IL | Miscellaneous Manufacturing339950 | — | ◇ UNVERIFIED |
| IGIdeal Gerit Drum Ring Mfg | Bedford Park | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| ITIdeal Troy CO | Peoria | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| IIIfco Ics-chicago INC | Lockport | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| IBIl Bell Telephone CO Dba At&t Illinois | Chicago | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| IBIl Bell Telephone CO Dba At&t Illinois | Chicago | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| IIIllico INC | Centralia | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| IWIllinois-american Water CO | Alton | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| IWIllinois-american Water Company San Koty Facility | Peoria | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| IBIllinois Bulk Carriers | Chicago Heights | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| ITIllinois Tire Recycling INC | Cicero | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| IHIndiana Harbor Belt | Franklin Park | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| IRIndiana Recycling & Renewable Fuels LLC | Chicago Heights | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| IJIngenco Joliet Facility | Joliet | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| IHIntermet Havana Foundry | Havana | IL | Primary Metal Manufacturing331511 | — | ◇ UNVERIFIED |
| IWIronwood West Subdivision | Champaign | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| JIJabco Industrial Services | Yorkville | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| JAJ & a Cartage | Palatine | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| JIJayvir INC | Litchfield | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| JWJd Weber Grain Storage & Drying | Osco | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| JJimax | Peoria | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| JJJ & J One Hour Cleaners INC | Bensenville | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| JVJks Ventures INC | Melrose Park | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
 Johns Manville - Waukegan | Waukegan | IL | Petroleum and Coal Products Manufacturing324122 | — | ◇ UNVERIFIED |
| JPJohnson-pate Pork | Dekalb | IL | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
