| 1 | CI | China Airlines | ICAO: CAL, Callsign: Dynasty, IATA Prefix: 297, | RC | AVCODES |
| 2 | CI | Cambria and Indiana R.R. Co. | 1/1975-1/1994; eliminated 10/1999; 7/2000-7/2005 | | NAKINA |
| 3 | CI | Cambria and Indiana R.R. Co. | 1/75-1/94; eliminated 10/99; 7/2000 | | NRHS |
| 4 | CI | CAMBRIA & INDIANA RAILROAD COMPANY | | | PWRC |
| 5 | CI | Cambria and Indiana Railroad | | | RSRV |
| 6 | CI | CAMBRIA AND INDIANA RAILROAD | | | SCAC4 |
| 7 | CI | Cambria and Indiana R.R. Co. | | USA | TRAFFIC |
| 8 | CI&L | Chicago, Indianapolis & Louisville Ry. | 7/1935-7/1936 | | NAKINA |
| 9 | CI&L | Chicago, Indianapolis & Louisville Ry. (Monon Route) | 8/1920-7/1932 | | NAKINA |
| 10 | CI&L | Chicago, Indianapolis & Louisville Ry. (Monon Route) | 23-Jul | | NRHS |
| 11 | CI&L | CHICAGO, INDIANAPOLIS & LOUISVILLE RWY. (MONON RAILROAD) | | | PWRC |
| 12 | CIA | Civil Aviation Authority of the Slovak Republic | Callsign: Calimera, | SK | AVCODES |
| 13 | CIA | CIPRA | Callsign: Cipra, | F | AVCODES |
| 14 | CIA | CIPRA | | F | AVCODES |
| 15 | CIA | Civil Aviation Authority | | | ICAO1 |
| 16 | CIAA | CONTINENTAL TRANSPORTATION | | | SCAC3 |
| 17 | CIAA | CAMERON LOGISTICS INC | | | SCAC4 |
| 18 | CIAB | CAROLINA AMERICAN TOURS | | | SCAC3 |
| 19 | CIAC | CICALESE, RICHARD TRUCKING | | | SCAC4 |
| 20 | CIAD | CIPOLLA, RICHARD | | | SCAC3 |
| 21 | CIAE | CRAIG IMPERIAL ACME CONSOLIDATORS I | | | SCAC3 |
| 22 | CIAE | CRAIG IMPERIAL ACME CONSOLIDATORS I | | | SCAC4 |
| 23 | CIAF | CAVALIER INTERNATIONAL AIR FREIGHT | | | SCAC4 |
| 24 | CIAG | CIRCLE A CARTAGE | | | SCAC3 |
| 25 | CIAH | COLUMBIA HAULERS INC | | | SCAC3 |
| 26 | CIAH | COSMO EXPRESS INTERNATIONAL CORPORA | | | SCAC4 |
| 27 | CIAJ | CODELITE INC | | | SCAC4 |
| 28 | CIAK | CTE INC | | | SCAC4 |
| 29 | CIAL | CONTINENTAL AIR FREIGHT | | | SCAC3 |
| 30 | CIAL | C I ANALYTICS | | | SCAC4 |
| 31 | CIAN | CHRISTIAN, PAUL | | | SCAC3 |
| 32 | CIAN | CHARIOTS AFIRE LLC | | | SCAC4 |
| 33 | CIAO | CAROLINA AIR CARGO | | | SCAC3 |
| 34 | CIAP | COLUMBINE CONSOLIDATED SERVICES INC | | | SCAC3 |
| 35 | CIAQ | CINCINNATI ASSEMBLEY & DISTRIBUTION | | | SCAC3 |
| 36 | CIAQ | CANUS INDUSTRIES | | | SCAC4 |
| 37 | CIAS | CHEVIN TRANSPORT | | | SCAC4 |
| 38 | CIAT | CITY AUTO TOWING INC | | | SCAC3 |
| 39 | CIAU | GEODIS RT ITALIA SRL | | I | BIC |
| 40 | CIAU | CIAT ROSSI SPA | | | SCAC4 |
| 41 | CIAU | | Real: CI | AUS | TRAFFIC |
| 42 | CIAV | CIAVARELLA, FRANK J | | | SCAC3 |
| 43 | CIAY | CAROLINA AUTO PROCESSING SERVICE | | | SCAC3 |
| 44 | CIAY | C I TRANSPORTATION | | | SCAC4 |
| 45 | CIB | Condor Berlin GmbH | IATA: DF, Callsign: Condor Berlin, | D | AVCODES |
| 46 | CIB | Condor | | | ICAO1 |
| 47 | CIBC | CONTINENTAL CARRIAGE LIMOUSINE SERV | | | SCAC3 |
| 48 | CIBD | C I TRANSPORT | | | SCAC4 |
| 49 | CIBE | C I CONTAINER LINE | | | SCAC4 |
| 50 | CIBF | CHEMICAL INTERCHANGE COMPANY | | | SCAC4 |
| 51 | CIBG | CARGILL INCORPORATED | | | SCAC4 |
| 52 | CIBI | CASAS INTERNATIONAL BROKERAGE INC | | | SCAC3 |
| 53 | CIBM | CONCORD INTERNATIONAL TRANSPORT INC | | | SCAC4 |
| 54 | CIBR | CIRCLE B RANCH | | | SCAC3 |
| 55 | CIBS | CITIBUS | | | SCAC3 |
| 56 | CIBT | CIRCLE B TRANSPORTATION SYSTEMS INC | | | SCAC3 |
| 57 | CIBT | CAPTRAN LOGISTICS LLC | | | SCAC4 |
| 58 | CIBU | CONT-ASPHALT LTD. | | CH | BIC |
| 59 | CIBU | CONT-ASPHALT LTD | | | SCAC4 |
| 60 | CIBW | CIRBIN INC | | | SCAC4 |
| 61 | CIBX | The CIT Group/Capital Finance, Inc. | added 7/2008 | | NAKINA |
| 62 | CIBX | THE CIT GROUP/CAPITAL FINANCE, INC. | | | PWRC |
| 63 | CIBX | CIT GROUP/CAPITAL FINANCE INC, THE | | | SCAC4 |
| 64 | CIC | ICC International Cargo Charters Canada Ltd.. d/b/a ICC Canada Ltd. | Callsign: Air Trader, | CDN | AVCODES |
| 65 | CIC | Celtic Airways Ltd. | Callsign: Celtic, | GB | AVCODES |
| 66 | CIC | ICC Canada | | | ICAO1 |
| 67 | CIC | Cedar Rapids and Iowa City Ry. Co. | 4/1938-7/2005 | | NAKINA |
| 68 | CIC | Cedar Rapids and Iowa City Ry. Co. | 4/38-7/2000 | | NRHS |
| 69 | CIC | CEDAR RAPIDS & IOWA CITY RAILWAY COMPANY (CRANDIC) | | | PWRC |
| 70 | CIC | Cedar Rapids and Iowa City Railway (Crandic) | | | RSRV |
| 71 | CICA | CISA SA | | CH | VKM |
| 72 | CICB | CITRANS CORP, THE | | | SCAC3 |
| 73 | CICC | CIAPUSCI, CHARLES A | | | SCAC3 |
| 74 | CICD | CICIONI, ALFRED J | | | SCAC3 |
| 75 | CICE | COMICAGE ENTERTAINMENT | | | SCAC4 |
| 76 | CICF | CICIONI, FRANK C | | | SCAC3 |
| 77 | CICH | COMBITRANS CONSOLIDATORS INC | | | SCAC4 |
| 78 | CICI | CENTRAL INDIANA CARTAGE | | | SCAC3 |
| 79 | CICI | CENTRAL ILLINOIS CARRIERS INC | | | SCAC4 |
| 80 | CICJ | CRUISE-IN-COMFORT INC | | | SCAC3 |
| 81 | CICJ | CANDO CONTRACTING INC | | | SCAC4 |
| 82 | CICK | CIRCLE C TRUCK LINES INC | | | SCAC3 |
| 83 | CICM | CHI-CAN TRANSPORT LTEE | | | SCAC3 |
| 84 | CICM | CHAMPION COACH INC | | | SCAC4 |
| 85 | CICN | CALSSIC BULK CARRIERS INC | | | SCAC4 |
| 86 | CICO | CICIO TRUCKING CO INC | | | SCAC3 |
| 87 | CICP | CAPRICORNIO TRANSPORT S.A | | | SCAC3 |
| 88 | CICQ | CIRCLE TRANSPORT INC | | | SCAC3 |
| 89 | CICR | CLIFTON IRON COMPANY RAILROAD | | | PWRC |
| 90 | CICR | CONTINENTAL CARRIERS INC | | | SCAC4 |
| 91 | CICS | CHEMICAL SERVICES CORP | | | SCAC3 |
| 92 | CICT | CIRCLE C TRANSPORTATION COMPANY | | | SCAC3 |
| 93 | CICU | CIMC CONTAINERS HOLDING COMPANY LTD | | PRC | BIC |
| 94 | CICU | CIE IMMOBILIERE & COMMERCE | | | SCAC3 |
| 95 | CICU | CHINA INTERNATIONAL MARINE CONTAINE | | | SCAC4 |
| 96 | CICV | CICALESE, VINCENT J | | | SCAC3 |
| 97 | CICV | CATTLE RIDE TRANSPORT | | | SCAC4 |
| 98 | CICW | CAMELI INTERNATIONAL AND CO. N V | | | SCAC3 |
| 99 | CICY | CIRCLE CITY TRANSPORT INC | | | SCAC3 |
| 100 | CID | Asia Continental Airlines | Callsign: Acid, | KZ | AVCODES |