| 1 | CIP | TAG City Air | Callsign: Cityways, ICAO code change to TEU | D | AVCODES |
| 2 | CIP | City Air Germany AG | IATA: 6E, Callsign: Cityways, Ceased operations on 27 February 2004. | D | AVCODES |
| 3 | CIPA | CLIPPER AIR FREIGHT FORWARDERS USA | | | SCAC3 |
| 4 | CIPA | CRUCES INTERNACIONALES PEGAS | | | SCAC4 |
| 5 | CIPB | CONTAINER INTERMODAL TRANSPORT INC | | | SCAC4 |
| 6 | CIPC | CHIEPPO COACHES | | | SCAC3 |
| 7 | CIPD | CITY PICKUP & DELIVERY | | | SCAC3 |
| 8 | CIPE | CITGO PETROLEUM CORPORATION | | | SCAC3 |
| 9 | CIPE | CRUSES INTERNACIONALES PE-GA | | | SCAC4 |
| 10 | CIPG | CHELLARAM SHIPPING (HONG KONG) LTD | | | SCAC4 |
| 11 | CIPI | CINCINNATI PIGGYBACK INT | | | SCAC3 |
| 12 | CIPL | CITY OF PORTLAND | | | SCAC3 |
| 13 | CIPM | CHIPMAN VAN & STORAGE INC | | | SCAC3 |
| 14 | CIPN | CIPPONERI, TOM TRUCKING | | | SCAC3 |
| 15 | CIPO | CITY PIONEER TRANSFER & STORAGE | | | SCAC3 |
| 16 | CIPQ | CITY PARCEL DELIVERY | | | SCAC3 |
| 17 | CIPS | AMEREN ENERGY GENERATING CO. [CENTRAL ILLINOIS PUBLIC SERVICE CORP.] | | | PWRC |
| 18 | CIPS | CITRA ENTERPRISE | | | SCAC3 |
| 19 | CIPT | CHIP TRUCKING INC | | | SCAC3 |
| 20 | CIPU | CAI INTERNATIONAL | | USA | BIC |
| 21 | CIPU | CAI International | | | RSRV |
| 22 | CIPU | CONVOY INTERCONTINENTAL TRANSPORT | | | SCAC3 |
| 23 | CIPU | CONTAINER APPLICATIONS INTERNATIONA | | | SCAC4 |
| 24 | CIPV | CREATIVE IRON PATIO | | | SCAC4 |
| 25 | CIPW | CHIPMAN RELOCATIONS | | | SCAC4 |
| 26 | CIPX | Ameren Energy Generating Co. | 7/2000-7/2005 (not listed) | | NAKINA |
| 27 | CIPX | Central Illinois Public Service Co. | added 10/1974; 1/1975-1/1980; eliminated 4/1993; 1/1994 (not listed); added 10/1995; eliminated 1/1999 | | NAKINA |
| 28 | CIPX | College Inn Food Products Co. (Union Refrigerator Transit Co.) | 7/1935 | | NAKINA |
| 29 | CIPX | College Inn Food Products Co. | 7/1932 | | NAKINA |
| 30 | CIPX | Central Illinois Public Service Co. | added 10/74; 1/75-1/80; eliminated 4/93; 1/94; added 10/95; eliminated 1/99 | | NRHS |
| 31 | CIPX | Ameren Energy Generating Co. | Jul-00 | | NRHS |
| 32 | CIPX | *COLLEGE INN FOOD PRODUCTS CO. | | | PWRC |
| 33 | CIPX | +AMEREN ENERGY GENERATING CO. [CENTRAL ILLINOIS PUBLIC SERVICE CORP.]} | | | PWRC |
| 34 | CIPX | Central Illinois Public Service (Ameren Energy Generating) | | | RSRV |
| 35 | CIPX | CENTRAL ILLINOIS EXPRESS INC | | | SCAC3 |
| 36 | CIPY | CENTRAL OIL AND SUPPLY CORPORATION | | | SCAC3 |
| 37 | CIPZ | AMEREN ENERGY GENERATING CO. [CENTRAL ILLINOIS PUBLIC SERVICE CORP.] | | | PWRC |