| 901 | KCMX | Potash Corp. of Saskatchewan, Inc. | added 10/90; eliminated 1/91 | | NRHS |
| 902 | KCMX | Saskterra Fertilizers Ltd. | added 1/91; eliminated 4/91 | | NRHS |
| 903 | KCMX | PLM International, Inc. | added 4/91; 1/94 | | NRHS |
| 904 | KCMX | *KANSAS CHEMICAL MANUFACTURING CO. | | | PWRC |
| 905 | KCMX | *(PLMX) PLM INTERNATIONAL, INC. [POTASH CORP. OF SASKATCHEWAN, INC.; SASKTERRA FERTILIZERS LTD.; KIDD CREEK MINES, LTD.] | | | PWRC |
| 906 | KCMX | Kidd Creek Mines | | | RSRV |
| 907 | KCMZ | KINDALL COAL MINE | | | PWRC |
| 908 | KCNF | KANAB COAL & FUEL | | | SCAC3 |
| 909 | KCNF | KANAB COAL & FUEL | | | SCAC4 |
| 910 | KCNR | KARTA CONTAINER & RECYCLING INC | | | SCAC3 |
| 911 | KCNS | KEITHS CHARCOAL & SAWMILL | | | SCAC3 |
| 912 | KCNT | KCH TRANSPORTATION INC | | | SCAC4 |
| 913 | KCNU | K-CON GMBH | | D | BIC |
| 914 | KCNU | K-CON GMBH | | | SCAC4 |
| 915 | KCNW | Kelley's Creek & Northwestern R.R. Co. | 1/1975-1/1994 | | NAKINA |
| 916 | KCNW | Kelley's Creek & Northwestern R.R. Co. | 1/75-1/94 | | NRHS |
| 917 | KCNW | RETIRED 04-29-93 ATP (411) [KELLEY'S CREEK & NORTWESTERN RR] | | | PWRC |
| 918 | KCNW | Kelley's Creek and Northwestern Railroad | | | RSRV |
| 919 | KCNW | KELLEYS CREEK AND NORTHWESTERN RAIL | | | SCAC3 |
| 920 | KCNY | KONECNY SISTERS TRUCKING | | | SCAC4 |
| 921 | KCOB | KIM CO | | | SCAC4 |
| 922 | KCOE | K & H COOPERATIVE OIL CO | | | SCAC4 |
| 923 | KCOH | KEIHIN CO LTD, THE | | | SCAC4 |
| 924 | KCOI | KRAMER CO INC, THE | | | SCAC3 |
| 925 | KCOL | K C OIL INC | | | SCAC4 |
| 926 | KCOM | KRALL COAL & OIL CO INC, THE | | | SCAC4 |
| 927 | KCON | KOLLER CONCRETE INC | | | SCAC3 |
| 928 | KCOP | KIERRA CORP | | | SCAC4 |
| 929 | KCOR | KSI CORP | | | SCAC4 |
| 930 | KCOT | KOCOT, HENRY C & SONS INC | | | SCAC3 |
| 931 | KCOU | UMICORE FINLAND OY | | FIN | BIC |
| 932 | KCOU | OMG KOKKOLA CHEMICALS OY | | | SCAC4 |
| 933 | KCOY | KEYSTONE COLONY | | | SCAC4 |
| 934 | KCPD | K C P D MOBILE HOME SERVICE INC | | | SCAC3 |
| 935 | KCPI | KANSAS CITY PARCEL INC | | | SCAC3 |
| 936 | KCPK | K C P K TRUCKING | | | SCAC3 |
| 937 | KCPK | KCPK TRUCKING INC | | | SCAC4 |
| 938 | KCPL | KANSAS CITY POWER & LIGHT | | | PWRC |
| 939 | KCPL | KOCH PIPELINES INC | | | SCAC3 |
| 940 | KCPL | KCP LOGISTICS LLC | | | SCAC4 |
| 941 | KCPS | KANSAS CITY PUBLIC SERVICE FREIGHT OPERATION | | | PWRC |
| 942 | KCPS | KANSAS CITY PUBLIC SERVICE FREIGHT | | | SCAC3 |
| 943 | KCPS | Kansas City Public Service Co. | | USA | TRAFFIC |
| 944 | KCPU | KOIKE MEDICAL CO LTD | | J | BIC |
| 945 | KCPX | Kemira Chemicals Canada Inc. | added 7/1999; 7/2000-7/2005 | | NAKINA |
| 946 | KCPX | Kemira Chemicals Canada Inc. | added 7/99; 7/2000 | | NRHS |
| 947 | KCPX | KEMIRA CHEMICALS CANADA, INC. | | | PWRC |
| 948 | KCPX | Kemira Chemicals Canada | | | RSRV |
| 949 | KCPX | KEMIRA CHEMICALS CANADA LTD | | | SCAC4 |
| 950 | KCR | Kolob Canyons Air Services | Callsign: Kolob, | USA | AVCODES |
| 951 | KCR | Kowloon-Canton Railway | City: Hong Kong | HK | TRAFFIC |
| 952 | KCR | KUBE CON rail GmbH | | DE | VKM |
| 953 | KCRC | K C RECYCLING LLC | | | SCAC4 |
| 954 | KCRG | KCR TRUCKING INC | | | SCAC4 |
| 955 | KCRS | KOWSKY, CHARLES RESOURCES INC | | | SCAC3 |
| 956 | KCRT | K-C REFRIGERATION TRANSPORT COMPANY | | | SCAC3 |
| 957 | KCRX | Kootenay Central Rail Services Ltd. | 7/2000-7/2005 (not listed) | | NAKINA |
| 958 | KCRX | Kansas City Refining Co. | 8/1920 | | NAKINA |
| 959 | KCRX | Kootenay Central Rail Services Ltd. | Jul-00 | | NRHS |
| 960 | KCRX | *KANSAS CITY REFINING CO. | | | PWRC |
| 961 | KCRX | +KOOTENAY CENTRAL RAIL SERVICES | | | PWRC |
| 962 | KCRX | Kootenay Central Rail Services | | | RSRV |
| 963 | KCRX | KOOTENAY CENTRAL RAIL SERVICES LTD | | | SCAC4 |
| 964 | KCRY | KENTUCKY CENTRAL RAILWAY | | | PWRC |
| 965 | KCS | Kansas City Southern Ry. Co. | 7/1965-7/2005 | | NAKINA |
| 966 | KCS | Kansas City Southern Ry. Co. | 7/65-7/2000 | | NRHS |
| 967 | KCS | KANSAS CITY SOUTHERN RAILWAY COMPANY | | | PWRC |
| 968 | KCS | Kansas City Southern Railway | | | RSRV |
| 969 | KCS | KANSAS CITY SOUTHERN RAILWAY COMPAN | | | SCAC4 |
| 970 | KCS | Kansas City Southern Railway Company | | USA | TRAFFIC |
| 971 | KCSC | KANSAS CITY SOUTHERN RAILWAY | | | SCAC4 |
| 972 | KCSD | KANSAS CITY SPECIAL DISPATCH | | | SCAC3 |
| 973 | KCSE | KING CHARTER SERVICE | | | SCAC3 |
| 974 | KCSE | KING CHARTER SERVICE | | | SCAC4 |
| 975 | KCSH | K C'S HOTSHOT INC | | | SCAC4 |
| 976 | KCSI | KEYSTONE CARRIERS INC | | | SCAC3 |
| 977 | KCSI | K & C SISTERS LOGISTICS INC | | | SCAC4 |
| 978 | KCSK | KCS TRUCKING | | | SCAC4 |
| 979 | KCSL | KAMLOOPS CHARTER SERVICE LTD | | | SCAC3 |
| 980 | KCSL | KELLY COVE SALMON LTD | | | SCAC4 |
| 981 | KCSM | Kansas City Southern de Mexico S.A. de C.V. | added 10/2007 | | NAKINA |
| 982 | KCSM | Kansas City Southern de Mexico S. de R.L. de C.V. | added 4/2007; eliminated 10/2007 | | NAKINA |
| 983 | KCSM | Kansas City Southern de Mexico S.A. de C.V. | added 7/2006; eliminated 4/2007 | | NAKINA |
| 984 | KCSM | KANSAS CITY SOUTHERN DE MEXICO SA DE CV | | | PWRC |
| 985 | KCSM | Kansas City Southern de Mexico | | | RSRV |
| 986 | KCSM | KANSAS CITY SOUTHERN DE MEXICO S DE | | | SCAC4 |
| 987 | KCSM | Kansas City Southern de Mexico | | MEX | TRAFFIC |
| 988 | KCSN | KOEHN CONTRACTING SERVICES INC | | | SCAC4 |
| 989 | KCSO | KC SPOTTING INC | | | SCAC4 |
| 990 | KCSP | K & C SHIPPING INC | | | SCAC3 |
| 991 | KCSP | K & C SHIPPING INC | | | SCAC4 |
| 992 | KCSS | KEANES CARTAGE SYSTEMS | | | SCAC4 |
| 993 | KCST | KANSAS CITY SOUTHERN TRANSPORT CO I | | | SCAC3 |
| 994 | KCST | KC CARGO SHUTTLE | | | SCAC4 |
| 995 | KCSU | KANTO KAGAKU SINGAPORE PTE LTD | | SGP | BIC |
| 996 | KCSU | KANSAS CITY SOUTHERN RAILWAY COMPANY | | | PWRC |
| 997 | KCSU | Kansas City Southern Railway | | | RSRV |
| 998 | KCSU | KANTO KAGAKU SINGAPORE PTE LTD | | | SCAC4 |
| 999 | KCSV | K/C SERVICE | | | SCAC3 |
| 1000 | KCSX | Kansas City Structural Steel Co. (White Eagle Oil & Refining Co.) | 8/1920 | | NAKINA |
