| 1 | CSS | Cess | Callsign: Cessavia, | GQ | AVCODES |
| 2 | CSS | Corse Aero Service | | F | AVCODES |
| 3 | CSS | Shun Fung Airlines Company Limited | IATA: O3, Callsign: Shun Feng, IATA Prefix: 921, | PRC | AVCODES |
| 4 | CSS | Chicago SouthShore & South Bend R.R. | added 4/1990; 1/1994-7/2005 | | NAKINA |
| 5 | CSS | Chicago South Shore & South Bend R.R. | 4/1938-10/1966 & 1/1975-1/1980; eliminated 4/1990 | | NAKINA |
| 6 | CSS | Chicago South Shore & South Bend R.R. | 4/38-10/66 & 1/75-1/80; eliminated 4/90 | | NRHS |
| 7 | CSS | Chicago SouthShore & South Bend R.R. | added 4/90; 1/94-7/2000 | | NRHS |
| 8 | CSS | CHICAGO SOUTHSHORE & SOUTH BEND RAILROAD | | | PWRC |
| 9 | CSS | Chicago South Shore and South Bend Railroad | | | RSRV |
| 10 | CSS | CHICAGO SOUTHSHORE & SOUTH BEND RAI | | | SCAC4 |
| 11 | CSS | Chicago South Shore & South Bend Railroad | | USA | TRAFFIC |
| 12 | CSS&SB | CHICAGO SOUTHSHORE & SOUTH BEND RAILROAD | | | PWRC |
| 13 | CSSA | CASSARINO TRUCKING INC | | | SCAC3 |
| 14 | CSSA | SF Airlines | Real: CSS | PRC | TRAFFIC |
| 15 | CSSB | CENTRIX LOGISTICS INC | | | SCAC4 |
| 16 | CSSC | COSSEY, CLIFFORD E | | | SCAC3 |
| 17 | CSSD | CASSIDY INC | | | SCAC3 |
| 18 | CSSDL | Cesloslovenská Správa Dopravních Letist | | CS | TRAFFIC |
| 19 | CSSE | CASSIDY'S EXPRESS, INC | | | SCAC3 |
| 20 | CSSE | CASSIDYS EXPRESS INC | | | SCAC4 |
| 21 | CSSF | CARRIER SUPPORT SERVICE LLC | | | SCAC4 |
| 22 | CSSG | CSC INC | | | SCAC3 |
| 23 | CSSH | CROSS HULLER NORTH AMERICA | | | SCAC4 |
| 24 | CSSI | CLEVELAND SWITCHING SERVICES | | | SCAC3 |
| 25 | CSSI | CLEVELAND SWITCHING SERVICES | | | SCAC4 |
| 26 | CSSJ | CASTRO & SONS | | | SCAC3 |
| 27 | CSSJ | CASSBURN CARRIERS | | | SCAC4 |
| 28 | CSSK | CSS DELIVERY | | | SCAC3 |
| 29 | CSSL | Canada Steamship Lines | 1/1975-1/1980 | | NAKINA |
| 30 | CSSL | Canada Steamship Lines | 1/75-1/80 | | NRHS |
| 31 | CSSL | CANADA STEAMSHIP LINES | | | PWRC |
| 32 | CSSL | CANADA STEAMSHIP LINES LTD | | | SCAC3 |
| 33 | CSSL | CANADA STEAMSHIP LINES INC | | | SCAC4 |
| 34 | CSSM | CROSS TRUCKING | | | SCAC3 |
| 35 | CSSM | CONSOLIDATED SYSTEMS | | | SCAC4 |
| 36 | CSSO | CASSO TRUCKING | | | SCAC3 |
| 37 | CSSO | CASS OIL CO INC | | | SCAC4 |
| 38 | CSSP | CLOVIS STONE & SUPPLY INC | | | SCAC3 |
| 39 | CSSP | CAN AMERICAN STONE SPREADER SALES L | | | SCAC4 |
| 40 | CSSQ | CS CARRIER SERVICE, INC. | | | SCAC3 |
| 41 | CSSQ | CARSS, ROBERT | | | SCAC4 |
| 42 | CSSS | CROSS-STAAB | | | SCAC3 |
| 43 | CSST | CROSSETT INC | | | SCAC3 |
| 44 | CSStL | CHICAGO SPRINGFIELD & St. LOUIS RWY | | | PWRC |
| 45 | CSSU | CONTAINER SALES (UK) LTD | | GB | BIC |
| 46 | CSSU | P & O NEDLLOYD BV | | | SCAC4 |
| 47 | CSSV | CENTRAL STATES REFRIGERATED SERVICE | | | SCAC3 |
| 48 | CSSW | CAPE STAR SHIPPING LIMITED | | | SCAC3 |
| 49 | CSSW | CALVARY TRANSPORTATION SERVICES INC | | | SCAC4 |
| 50 | CSSX | CITY OF SPENCER SPUR | | | PWRC |
| 51 | CSSY | CARRIERS SECUREMENT SYSTEMS INC | | | SCAC3 |
| 52 | CSSZ | *CHICAGO SOUTHSHORE & SOUTH BEND RAILROAD | | | PWRC |
| 53 | CSSZ | *CHRYSLER STERLING STAMPING | | | PWRC |
