| 5001 | KSLE | KESLER RODEO | | | SCAC4 |
| 5002 | KSLI | K S L INCORPORATED | | | SCAC3 |
| 5003 | KSLM | KS LIMITED | | | SCAC4 |
| 5004 | KSLO | KEYSTONE LOGISTICS INC | | | SCAC4 |
| 5005 | KSLQ | KAPRIFOL SHIPPING LIMITED | | | SCAC4 |
| 5006 | KSLR | KESSLER TRUCKING INC | | | SCAC4 |
| 5007 | KSLT | KESSEL TRUCKING CO INC | | | SCAC3 |
| 5008 | KSLU | SHANGHAI METAL CORPORATION | | PRC | BIC |
| 5009 | KSLW | KERROWGLASS SHIPPING LIMITED | | | SCAC4 |
| 5010 | KSM | Kosmos | Callsign: Kosmos, | RUS | AVCODES |
| 5011 | KSM | Kosmos | | | ICAO1 |
| 5012 | KSM | Konsortium Südtiroler Mietwagenunternehmer | | I | TRAFFIC |
| 5013 | KSMA | K-SPORTS MARINE | | | SCAC4 |
| 5014 | KSMB | KERR & SONS MOBILE SERVICE INC | | | SCAC3 |
| 5015 | KSMB | KSM BROKERAGE | | | SCAC4 |
| 5016 | KSMC | KSM CARRIERS INC | | | SCAC3 |
| 5017 | KSMG | K & S MOVING SYSTEMS INC | | | SCAC3 |
| 5018 | KSMH | KANSAS MOBILE HOME TRANSFER | | | SCAC3 |
| 5019 | KSMI | KSMI INC | | | SCAC4 |
| 5020 | KSMO | K & M SILO | | | SCAC3 |
| 5021 | KSMP | KS MARINE CORPORATION | | | SCAC4 |
| 5022 | KSMS | K'S MOTOR SERVICE | | | SCAC3 |
| 5023 | KSMV | KASTER MOVING CO | | | SCAC3 |
| 5024 | KSMV | KASTER MOVING CO INC | | | SCAC4 |
| 5025 | KSMX | Kosmos Cement Co., Inc. | added 4/1981; eliminated 1/1989 | | NAKINA |
| 5026 | KSMX | The Flintkote Co./Kosmos Cement Division | added 4/1978; 1/1980; eliminated 4/1981 | | NAKINA |
| 5027 | KSMX | The Flintkote Co., Eastern Cement Region | added 4/1976; eliminated 4/1978 | | NAKINA |
| 5028 | KSMX | The Flintkote Co., Diamond Kosmos Cement Division | added 4/1972; 1/1975; eliminated 4/1976 | | NAKINA |
| 5029 | KSMX | Kosmos Portland Cement Co. | 4/1947 (not listed); 1/1950-4/1970; eliminated 4/1972 | | NAKINA |
| 5030 | KSMX | Kosmos Portland Cement Co. | 1/52-4/70; eliminated 4/72 | | NRHS |
| 5031 | KSMX | The Flintkote Co., Diamond Kosmos Cement Division | added 4/72; 1/75; eliminated 4/76 | | NRHS |
| 5032 | KSMX | The Flintkote Co., Eastern Cement Region | added 4/76; eliminated 4/78 | | NRHS |
| 5033 | KSMX | The Flintkote Co./Kosmos Cement Division | added 4/78; 1/80; eliminated 4/81 | | NRHS |
| 5034 | KSMX | Kosmos Cement Co., Inc. | added 4/81; eliminated 1/89 | | NRHS |
| 5035 | KSMX | KOSMOS CEMENT CO. (FLINTKOTE CO.) | | | PWRC |
| 5036 | KSMX | Kosmos Cement | | | RSRV |
| 5037 | KSMX | KOSMOS PORTLAND CEMENT CO | | | SCAC3 |
| 5038 | KSMX | Kosmos Cement Co., Inc. | | USA | TRAFFIC |
| 5039 | KSND | KS & D | | | SCAC4 |
| 5040 | KSNI | KOCH, STAN & SONS TRUCKING INC (INT | | | SCAC4 |
| 5041 | KSOB | KS OBO V/DANSKIB XVII APS GLASGOW | | | SCAC4 |
| 5042 | KSOD | Kaschau-Oderberger Bahn | | H | TRAFFIC |
| 5043 | KSOE | KELSOE OIL COMPANY | | | SCAC4 |
| 5044 | KSOM | KUSTOM TRANSPORT FORWARDING INC | | | SCAC3 |
| 5045 | KSON | K TRUCKING & SON INC | | | SCAC4 |
| 5046 | KSOT | KENMAR & SONS TRUCKING INC | | | SCAC3 |
| 5047 | KSOT | K-SEA OPERATING PARTNERSHIP L P | | | SCAC4 |
| 5048 | KSOYUZ | Soyuz-Avto Kiev | | UA | TRAFFIC |
| 5049 | KSP | Servicios Aereos Especializados En Transportes Petroleros | Callsign: Seap, | CO | AVCODES |
| 5050 | KSP | Servicios Aereos Expecializados En Transportes Pet | | | ICAO1 |
| 5051 | KSPC | KASPAR CARTAGE INC | | | SCAC3 |
| 5052 | KSPD | KANSAS CITY PICKUP & DELIVERY | | | SCAC3 |
| 5053 | KSPG | KSP LOGISTICS INC | | | SCAC4 |
| 5054 | KSPM | KASPER MOVERS INC | | | SCAC3 |
| 5055 | KSPM | KOSTAS SCRAP METALS INC | | | SCAC4 |
| 5056 | KSPR | K SCRAP RESOURSES | | | SCAC3 |
| 5057 | KSPR | KLASSEN PETERS, DAVID | | | SCAC4 |
| 5058 | KSPT | K S P TRUCK LINES, INC | | | SCAC3 |
| 5059 | KSPT | K S P TRUCK LINES INC | | | SCAC4 |
| 5060 | KSPU | KINGCON CONTAINER STORAGE INC | | CDN | BIC |
| 5061 | KSR | Sanrise | Callsign: Kazak Sunrise, | KZ | AVCODES |
| 5062 | KSR | Köstner -Schienenbusreisen | | DE | VKM |
| 5063 | KSRC | KSR COMPANY INC | | | SCAC4 |
| 5064 | KSRL | K-SCRAP RESOURCES LTD | | | SCAC4 |
| 5065 | KSRP | K-S TRANSPORT INC | | | SCAC3 |
| 5066 | KSRS | KAISER SHIPPING | | | SCAC4 |
| 5067 | KSRU | CONTAINERPARTNER AS | | | SCAC4 |
| 5068 | KSRX | KOSCIUSKO & SOUTHWESTERN RAILWAY | | | PWRC |
| 5069 | KSRY | Kosciusko & Southwestern Ry. | 7/2005 | | NAKINA |
| 5070 | KSRY | KOSCIUSKO & SOUTHWESTERN RAILWAY | | | PWRC |
| 5071 | KSRY | Kosciusko and Southwestern Railway | | | RSRV |
| 5072 | KSRY | KOSCIUSKO SOUTHWESTERN RAILWAY | | | SCAC4 |
| 5073 | KSS | Raytheon Travel Air | Callsign: Kansas, | USA | AVCODES |
| 5074 | KSS | Raytheon Travel Air | | | ICAO1 |
| 5075 | KSSB | KESSLER, S & B | | | SCAC4 |
| 5076 | KSSC | KACIOS SHIPPING INC | | | SCAC3 |
| 5077 | KSSE | KESSEL LUMBER SUPPLY INC | | | SCAC3 |
| 5078 | KSSE | KSS LINE LTD | | | SCAC4 |
| 5079 | KSSG | KOMMANDITSELSKABET SWANMILL SHIPPIN | | | SCAC3 |
| 5080 | KSSH | KANSAS SHUTTLE | | | SCAC3 |
| 5081 | KSSH | KSS LEASING INC | | | SCAC4 |
| 5082 | KSSJ | K S S TRUCKING LTD | | | SCAC4 |
| 5083 | KSSL | KESSLER TRUCKING COMPANY | | | SCAC3 |
| 5084 | KSSL | KESSLER TRUCKING COMPANY LLC | | | SCAC4 |
| 5085 | KSSN | KESSON CONSTRUCTION INC | | | SCAC3 |
| 5086 | KSSN | KASSIAN MARITIME NAVIGATION AGENCY | | | SCAC4 |
| 5087 | KSSO | K/S SIBOTI | | | SCAC4 |
| 5088 | KSSQ | KEISER SOIL SERVICE | | | SCAC3 |
| 5089 | KSSR | KINGDOM SUPPORT SERVICES INC | | | SCAC4 |
| 5090 | KSST | KSS TRANSPORTATION | | | SCAC3 |
| 5091 | KSSU | KERR STEAMSHIP COMPANY INC. (KSSU) | | | SCAC3 |
| 5092 | KSSU | KERR STEAMSHIP COMPANY INC | | | SCAC4 |
| 5093 | KSSV | KAWANISHI SHIPPING SERVICE (HK) LTD | | | SCAC3 |
| 5094 | KST | PTL Luftfahrtunternehmen GmbH. | IATA: PQ, Callsign: King Star, Designator PQ recalled by IATA | D | AVCODES |
| 5095 | KST | PTL Luftfahrtunternehmen GmbH. | Callsign: King Star, Designator PQ recalled by IATA | D | AVCODES |
| 5096 | KST | PTL Luftfahrtunternehemen | | | ICAO1 |
| 5097 | KSTA | KRIS'S TRANSPORT | | | SCAC3 |
| 5098 | KSTC | KST CORP | | | SCAC3 |
| 5099 | KSTC | KITTSON AUTO & IMPLEMENT INC | | | SCAC4 |
| 5100 | KSTD | K & S TRUCKING | | | SCAC3 |
