| 9501 | CLT | Caribbean Air Transport | | | ICAO1 |
| 9502 | CLTA | L CASAS TRANSPORTES | | | SCAC4 |
| 9503 | CLTB | CALA TRANSPORTATION, INC | | | SCAC3 |
| 9504 | CLTB | CALA TRANSPORTATION INC | | | SCAC4 |
| 9505 | CLTC | CLAUDES TRUCK & TRAILER SERVICE INC | | | SCAC3 |
| 9506 | CLTC | CAPITAL TRUCKING | | | SCAC4 |
| 9507 | CLTD | CENTRAL TRUCK LINES LIMITED | | | SCAC3 |
| 9508 | CLTD | CALVILLO, L M TRUCKING | | | SCAC4 |
| 9509 | CLTF | CLINTON TRANSFER & STORAGE COMPANY | | | SCAC3 |
| 9510 | CLTF | COHO FARMS | | | SCAC4 |
| 9511 | CLTG | CLIFFS TOWING LTD | | | SCAC4 |
| 9512 | CLTH | CLOUTHIER, RONALD L INC | | | SCAC3 |
| 9513 | CLTI | CLEARY TRUCKING | | | SCAC3 |
| 9514 | CLTK | CASE, LONNIE, TRUCKING, INC | | | SCAC3 |
| 9515 | CLTL | CLARK, BILL, TRUCK LINE, INC | | | SCAC3 |
| 9516 | CLTM | CAROLINA TOURS UNLIMITED OF GARNER | | | SCAC3 |
| 9517 | CLTN | CLAY TRUCKING INC | | | SCAC3 |
| 9518 | CLTO | COOL TRANSPORTATION | | | SCAC3 |
| 9519 | CLTO | CLASICA TORTILLERIA S A DE C V | | | SCAC4 |
| 9520 | CLTP | CLARK TRUCKING COMPANY | | | SCAC3 |
| 9521 | CLTQ | CLARKE TRAFFIC SERVICE | | | SCAC3 |
| 9522 | CLTR | CLINTON TRANSFER, INC | | | SCAC3 |
| 9523 | CLTR | CLEARY TRANSPORTATION COMPANY INC | | | SCAC4 |
| 9524 | CLTS | CALENDAR TRANSPORT INC | | | SCAC4 |
| 9525 | CLTT | COASTAL TRANSPORT CO INC | | | SCAC3 |
| 9526 | CLTU | SOGECO INTERNATIONAL SA | | CH | BIC |
| 9527 | CLTU | CHEMICAL LEAMAN TANK LINES INC. | | | PWRC |
| 9528 | CLTU | Chemical Leaman Tank Lines | | | RSRV |
| 9529 | CLTU | COING TAINER | | | SCAC3 |
| 9530 | CLTU | COLT CONTAINER LEASING AND TRADING | | | SCAC4 |
| 9531 | CLTV | CLOSE TRUCKING | | | SCAC3 |
| 9532 | CLTV | C & L TOWING SERVICE INC | | | SCAC4 |
| 9533 | CLTW | COLANDREA TRUCKING INC | | | SCAC3 |
| 9534 | CLTW | CLT TRUCKING INC | | | SCAC4 |
| 9535 | CLTX | Cloro de Tehuantepec, S.A. de C.V. | added 1/1988; eliminated 4/1989; 1/1994-7/2005 (not listed) | | NAKINA |
| 9536 | CLTX | Cominco Ltd. | added 4/1967; eliminated 7/1968 | | NAKINA |
| 9537 | CLTX | Union Tank Car Co. | added 7/1968; 4/1970; eliminated 4/1970 | | NAKINA |
| 9538 | CLTX | Coltexo Corp. | 7/1935-4/1961; eliminated 1/1962 | | NAKINA |
| 9539 | CLTX | Coltexo Corp. | 4/38-4/61; eliminated 1/62 | | NRHS |
| 9540 | CLTX | Cominco Ltd. | added 4/67; eliminated 7/68 | | NRHS |
| 9541 | CLTX | Union Tank Car Co. | added 7/68; 4/70; eliminated 4/70 | | NRHS |
| 9542 | CLTX | Cloro de Tehuantepec, S.A. de C.V. | added 1/88; eliminated 4/89; 1/94-7/2000 | | NRHS |
| 9543 | CLTX | *COLTEXO CORP. | | | PWRC |
| 9544 | CLTX | *COMINCO LTD. (UNION TANK CAR CO.) | | | PWRC |
| 9545 | CLTX | +CLORO DE TEHUANTEPEC, SA DE CV | | | PWRC |
| 9546 | CLTX | Cloro de Tehuantepec de CV | | | RSRV |
| 9547 | CLTY | CLEARFIELD TRANSPORTATION CO INC | | | SCAC3 |
| 9548 | CLU | Avanti Aviation Aachen Luftfahfitgesellschaft mbH | Callsign: Carolus, Name changed to Triple Alpha Luftfahfitgesellschaft mbH. Founded in 1995 | D | AVCODES |
| 9549 | CLU | Club Air (Europe) Ltd. | Callsign: Club, | GB | AVCODES |
| 9550 | CLU | Triple Alpha Luftfahfitgesellschaft mbH | Callsign: Carolus, Ceased operation in July 2011. Name changed from Avanti Aviation Aachen Luftfahfitgesellschaft mbH. Entered administration in July 2011 | D | AVCODES |
| 9551 | CLU | Cargologicair Ltd. | IATA: P3, Callsign: Firebird, IATA Prefix: 560, Ceased operations on 24 February 2020. AOC Reinstated on 22/04/2020. Part of Volga-Dnepr Group. | GB | AVCODES |
| 9552 | CLU | Triple Alpha | | | ICAO1 |
| 9553 | CLU | CROWN LIMOUSINE SERVICE | | | SCAC4 |
| 9554 | CLUA | CONCEPTUM LOGISTICS (USA) LLC | | | SCAC4 |
| 9555 | CLUB | COLUMBIA TUG BOAT CO | | | SCAC3 |
| 9556 | CLUB | CLUB CAR INC | | | SCAC4 |
| 9557 | CLUB | Club Transportation | | USA | TRAFFIC |
| 9558 | CLUC | CONNECTICUT LUMBER CARRIERS INC | | | SCAC3 |
| 9559 | CLUC | CASTILLO CORONADO, LUCINA | | | SCAC4 |
| 9560 | CLUE | COLUMBIA EXPORT PACKERS INC | | | SCAC3 |
| 9561 | CLUG | COLUMBUS AIR CARGO | | | SCAC3 |
| 9562 | CLUH | CLOUGH, H R | | | SCAC4 |
| 9563 | CLUI | C L U INC | | | SCAC3 |
| 9564 | CLUJ | CARROLL TRUCK LINES (A DIVISION OF | | | SCAC3 |
| 9565 | CLUJ | Compania de Transport Public | City: Cluj | RO | TRAFFIC |
| 9566 | CLUK | COLLINS, LUKE | | | SCAC3 |
| 9567 | CLUL | CLASSIC TRUCK LINES | | | SCAC3 |
| 9568 | CLUM | COLUMBIA TRANSFER INC | | | SCAC3 |
| 9569 | CLUN | CLUNE TRANSFER | | | SCAC3 |
| 9570 | CLUN | CLUNE TRANSFER | | | SCAC4 |
| 9571 | CLUP | COLUSSY TRUCKING INC | | | SCAC3 |
| 9572 | CLUP | CLARK TRUCK PARTS INC | | | SCAC4 |
| 9573 | CLUQ | CASTENS, LOUIS | | | SCAC3 |
| 9574 | CLUR | CLOUTIER-LOTT ENTERPRISES, INC | | | SCAC3 |
| 9575 | CLUR | CAL STATE AUTO PARTS INC | | | SCAC4 |
| 9576 | CLUS | CLAUSSEN, THOMAS E | | | SCAC3 |
| 9577 | CLUT | CLEVELAND UNION TERMINALS COMPANY | | | PWRC |
| 9578 | CLUT | CLOUTIER, NORMAND TRANSPORT INC | | | SCAC3 |
| 9579 | CLUV | COLUMBUS MOVING & STORAGE INC | | | SCAC3 |
| 9580 | CLUX | Chillicothe Lumber Co. | added 10/1974; 1/1975; eliminated 10/1977 | | NAKINA |
| 9581 | CLUX | Chillicothe Lumber Co. | added 10/74; 1/75 | | NRHS |
| 9582 | CLUX | CHILLICOTHE LUMBER CO. | | | PWRC |
| 9583 | CLUY | COMMERCIAL TRANSPORTATION INC | | | SCAC3 |
| 9584 | CLV | CAL Aviation, S.A. | Callsign: Calavia, | GR | AVCODES |
| 9585 | CLV | Clover Aero, Inc. | Callsign: Clover Air, | USA | AVCODES |
| 9586 | CLV | Lom Praha Flying School | | | ICAO1 |
| 9587 | CLVA | CLOVER INTERNATIONAL | | | SCAC4 |
| 9588 | CLVB | CULVER TRANSIT INC | | | SCAC4 |
| 9589 | CLVC | CLOVER CLUB FOODS CO | | | SCAC3 |
| 9590 | CLVC | COLVINS INC | | | SCAC4 |
| 9591 | CLVD | CLEVELAND TANKERS | | | SCAC3 |
| 9592 | CLVE | CLEAN VENTURE INC | | | SCAC4 |
| 9593 | CLVF | CLOVERLEAF TRUCKING INC | | | SCAC3 |
| 9594 | CLVF | CLOVER FARMS TRANSPORTATION CO | | | SCAC4 |
| 9595 | CLVG | CAL-SECURITY MOVING & STORAGE INC | | | SCAC3 |
| 9596 | CLVG | CLAVOS TRUCKIN | | | SCAC4 |
| 9597 | CLVH | CAL-VAN TRANSPORTATION SERVICES INC | | | SCAC3 |
| 9598 | CLVI | CLOVER INC | | | SCAC3 |
| 9599 | CLVK | CLOVER TRUCKING | | | SCAC4 |
| 9600 | CLVL | CALVIN COLLEGE & SEMINARY | | | SCAC3 |
