| 17101 | CTSA | COMPETITIVE TRANSPORTATION INCORPOR | | | SCAC4 |
| 17102 | CTSB | CITY TOWING INC | | | SCAC3 |
| 17103 | CTSB | CTS | | | SCAC4 |
| 17104 | CTSC | Calgary Transit System | Real: CTS | CDN | TRAFFIC |
| 17105 | CTSD | C T S ENTERPRISES INC | | | SCAC3 |
| 17106 | CTSE | Chicago, Terre Haute and Southeastern Ry. Co. (Chicago, Milwaukee, St. Paul and Pacific R.R. Co.) | 10/1966 | | NAKINA |
| 17107 | CTSE | Chicago, Terre Haute & Southeastern Ry. | 4/1938-7/1965 | | NAKINA |
| 17108 | CTSE | Chicago, Terre Haute & Southeastern Ry. Co. (Chicago, Milwaukee, St. Paul and Pacific R.R. Co.) | 7/1936 | | NAKINA |
| 17109 | CTSE | Chicago, Terre Haute & Southeastern Ry. | 4/38-7/65 | | NRHS |
| 17110 | CTSE | Chicago, Terre Haute and Southeastern Ry. Co. (Chicago, Milwaukee, St. Paul and Pacific R.R. Co.) | Oct-66 | | NRHS |
| 17111 | CTSE | CHICAGO, TERRE HAUTE & SOUTEASTERN RY. | | | PWRC |
| 17112 | CTSF | COAST TRANSFER & STORAGE | | | SCAC3 |
| 17113 | CTSG | CTS INC | | | SCAC3 |
| 17114 | CTSH | CHRISTMAN, SCOTT A | | | SCAC4 |
| 17115 | CTSI | CENTURY TRANSPORTATION SERVICE | | | SCAC3 |
| 17116 | CTSI | CENTURY TRANSPORTATION SERVICE | | | SCAC4 |
| 17117 | CTSJ | COLUMBIA TRANSIT CORPORATION | | | SCAC3 |
| 17118 | CTSJ | COMMERCIAL TRANSPORT SERVICE INC | | | SCAC4 |
| 17119 | CTSK | CTS TRUCKING | | | SCAC3 |
| 17120 | CTSK | CARTER TRANSPORTATION SOLUTIONS LLC | | | SCAC4 |
| 17121 | CTSL | CUSTOM TRANSPORT LTD | | | SCAC3 |
| 17122 | CTSL | CENTURY LOGISTICS PLUS LLC | | | SCAC4 |
| 17123 | CTSM | CONTRACT TRANSPORTATION SYSTEMS CO. | | | SCAC3 |
| 17124 | CTSM | C TRANSPORTATION SYSTEMS INC | | | SCAC4 |
| 17125 | CTSN | CITRUS TRANSPORT SERVICE | | | SCAC3 |
| 17126 | CTSO | CANNON TRANSFER & STORAGE COMPANY | | | SCAC3 |
| 17127 | CTSO | CHEMICAL TRADER SHIPPING COMPANY LI | | | SCAC4 |
| 17128 | CTSP | CLASSIC TRANSPORTATION SERVICES INC | | | SCAC3 |
| 17129 | CTSP | CLASSIC TRANSPORTATION SERVICES INC | | | SCAC4 |
| 17130 | CTSQ | CHAMBLESS TRANSFER AND STORAGE COMP | | | SCAC3 |
| 17131 | CTSQ | CARGO TRANSPORTATION SERVICES INC | | | SCAC4 |
| 17132 | CTSR | CUMBRES & TOLTEC SCENIC RAILROAD | | | PWRC |
| 17133 | CTSR | CINCINNATI TRANSFER & STORAGE CO IN | | | SCAC3 |
| 17134 | CTSR | CSM TRANSPORTATION SERVICES INC | | | SCAC4 |
| 17135 | CTSR | Cumbres and Toltec Scenic Railroad | Real: C&TS | USA | TRAFFIC |
| 17136 | CTSS | CONTRACT TRANSPORT SERVICES INC | | | SCAC3 |
| 17137 | CTSS | CUSTOM TRUCK SALES INC | | | SCAC4 |
| 17138 | CTST | CTS TRANSPORTATION LLC | | | SCAC4 |
| 17139 | CTSU | CYCLIFE FRANCE SA | | F | BIC |
| 17140 | CTSU | BIBBY BROS CO. | | | PWRC |
| 17141 | CTSU | Bibby Bros (Socodei) | | | RSRV |
| 17142 | CTSU | SOCODEI | | | SCAC4 |
| 17143 | CTSW | CHASE TRANSPORTATION SERVICES | | | SCAC3 |
| 17144 | CTSW | CON-TECH SYSTEMS LTD | | | SCAC4 |
| 17145 | CTSX | CTC Cement Manufacturing Corp. | eliminated 1/2008 | | NAKINA |
| 17146 | CTSX | CTS Cement Manufacturing Corp. | added 4/2007 | | NAKINA |
| 17147 | CTSX | Chem Comp Systems, Inc. d/b/a CTS Cement Manufacturing, Inc.) | 7/2000-7/2005 (not listed) | | NAKINA |
| 17148 | CTSX | Chem Comp Systems, Inc. | added 1/1997; eliminated 4/1997 | | NAKINA |
| 17149 | CTSX | Chem Comp Systems, Inc. d/b/a CTS Cement Manufacturing, Inc.) | 1/1994 (not listed) | | NAKINA |
| 17150 | CTSX | Coordinated Transportation Systems, Inc. | added 7/1956; 10/1957; eliminated 1/1958 | | NAKINA |
| 17151 | CTSX | Coordinated Transportation Systems, Inc. | added 7/56; 10/57; eliminated 1/58 | | NRHS |
| 17152 | CTSX | Chem Comp Systems, Inc. d/b/a CTS Cement Manufacturing, Inc.) | Jan-94 | | NRHS |
| 17153 | CTSX | Chem Comp Systems, Inc. | added 1/97; eliminateed 4/97 | | NRHS |
| 17154 | CTSX | Chem Comp Systems, Inc. d/b/a CTS Cement Manufacturing, Inc.) | Jul-00 | | NRHS |
| 17155 | CTSX | *COORDINATED TRANSPORTATION SYSTEMS, INC. | | | PWRC |
| 17156 | CTSX | +CHEM COMP SYSTEMS, INC. (DBA CTS CEMENT MANUFACTURING CORP.) | | | PWRC |
| 17157 | CTSX | CTS Cement Manufacturing (Chem Comp Systems) | | | RSRV |
| 17158 | CTSX | CTS CEMENT MANUFACTURING CORPORATIO | | | SCAC4 |
| 17159 | CTSY | COOPERATIVE SUPPLY INC | | | SCAC4 |
| 17160 | CTSZ | CAROTRANS INTERNATIONAL | | | PWRC |
| 17161 | CTSZ | Carotrans International | | | RSRV |
| 17162 | CTSZ | CAROTRANS INTERNATIONAL | | | SCAC4 |
| 17163 | CTT | Custom Air Transport, Inc. | Callsign: Catt, Ceased operations on 15 September 2002. Designator DG* recalled by IATA | USA | AVCODES |
| 17164 | CTT | Custom Air Transport, Inc. | IATA: DG, Callsign: Catt, Designator DG* recalled by IATA | USA | AVCODES |
| 17165 | CTT | Custom Air Transport, Inc. | IATA: 5R, Callsign: Catt, Comenced operations 09 December 1995. | USA | AVCODES |
| 17166 | CTT | Custom Air Transport | | | ICAO1 |
| 17167 | CTT | Connecticut Transit (CT Transit) | | USA | TRAFFIC |
| 17168 | CTTA | CONTINENTAL COAL & SHIPPING INC | | | SCAC3 |
| 17169 | CTTB | CITATION TRANSPORTATION INC | | | SCAC3 |
| 17170 | CTTB | CONTINENTAL TRANSPORT INC | | | SCAC4 |
| 17171 | CTTC | CIRCLE TRANSPORT CORPORATION | | | SCAC3 |
| 17172 | CTTD | CLEAN HARBORS CATALYST TECHNOLOGIES | | | SCAC4 |
| 17173 | CTTE | CENTRAL TRANSPORT INC | | | SCAC3 |
| 17174 | CTTF | CATENCAMP TRANSFER & STORAGE INC | | | SCAC3 |
| 17175 | CTTG | CATOM TRUCKING INC | | | SCAC3 |
| 17176 | CTTG | COIL TRANS TRUCKING INC | | | SCAC4 |
| 17177 | CTTH | CT TRANSPORT | | | SCAC4 |
| 17178 | CTTI | CORNET TRANSPORT INC | | | SCAC3 |
| 17179 | CTTI | CORNET TRANSPORT INC | | | SCAC4 |
| 17180 | CTTJ | CT TRANSPORTATION | | | SCAC3 |
| 17181 | CTTJ | COLUMBIA TAPING TOOLS LTD | | | SCAC4 |
| 17182 | CTTK | COMET TRUCK LINE, INC | | | SCAC3 |
| 17183 | CTTK | CHAMBERS, TOMMY TRUCKING | | | SCAC4 |
| 17184 | CTTL | CT TRANSPORT LLC | | | SCAC4 |
| 17185 | CTTL | CTT Livorno | | I | TRAFFIC |
| 17186 | CTTM | CONN-MASS PIPE LINE INC | | | SCAC3 |
| 17187 | CTTM | CONNECT TELECOMMUNICATIONS SOLUTION | | | SCAC4 |
| 17188 | CTTN | CAN-TRUCK TRANSPORTATION DIVISION | | | SCAC3 |
| 17189 | CTTO | C TRANSPORTATION CO | | | SCAC3 |
| 17190 | CTTO | CIRCLE T TRANSORTATION INC | | | SCAC4 |
| 17191 | CTTP | CT TRANSPOPRTATION | | | SCAC4 |
| 17192 | CTTQ | C T TRANSPORTATION SYSTEMS | | | SCAC3 |
| 17193 | CTTQ | CTT INC | | | SCAC4 |
| 17194 | CTTS | CONTAINER TRANSFER SERVICE | | | SCAC3 |
| 17195 | CTTT | CONTINENTAL TRUCK & TOWING CO | | | SCAC3 |
| 17196 | CTTU | CANTAS KIMYA SANAYI TICARET A.S. | | TR | BIC |
| 17197 | CTTV | CRESTON TRANSPORTATION INC | | | SCAC4 |
| 17198 | CTTW | COTTONWOOD COMMODITIES | | | SCAC4 |
| 17199 | CTTX | TTX Co. | added 1/1992; 1/1994-7/2005 | | NAKINA |
| 17200 | CTTX | Trailer Train Co. | added 4/1961; 4/1961-1/1975; eliminated 1/1976; added 4/1976; 1/1980; eliminated 1/1992 | | NAKINA |
