| 1 | KL | KLM Royal Dutch Airlines (Koninklijke Luchtvaart Maatschappij N.V.) | ICAO: KLM, Callsign: KLM, IATA Prefix: 074, | NL | AVCODES |
| 2 | KL | other city transport | City: Kuala Lumpur | MAL | TRAFFIC |
| 3 | KLA | Air Lithuania | IATA: TT, Callsign: Kaunas, IATA Prefix: 843, | LT | AVCODES |
| 4 | KLA | SKA SA Aircraft Leasing (Pty) Ltd | | ZA | AVCODES |
| 5 | KLA | Air Lithuania | IATA: TT | | ICAO1 |
| 6 | KLA | Koniklije Landmacht | | NL | TRAFFIC |
| 7 | KLAB | KOLA BUILDING MOVERS LTD | | | SCAC4 |
| 8 | KLAC | KLASSIC EXPRESS INC | | | SCAC4 |
| 9 | KLAE | K-LINE AMERICA | | | SCAC3 |
| 10 | KLAF | KLEINS MOVING & STORAGE INC | | | SCAC3 |
| 11 | KLAF | KLEINS MOVING & STORAGE INC | | | SCAC4 |
| 12 | KLAI | KEONI LINES LLC | | | SCAC4 |
| 13 | KLAL | K & L AUTOMOTIVE | | | SCAC4 |
| 14 | KLAM | KLAMATH MOVING & STORAGE CO | | | SCAC3 |
| 15 | KLAM | KLAMATH MOVING & STORAGE COMPANY IN | | | SCAC4 |
| 16 | KLAP | KLAPEC EXPRESS INC | | | SCAC4 |
| 17 | KLAP | UAB Klaipedos autobusu parkas | City: Klaipeda | LT | TRAFFIC |
| 18 | KLAQ | KNOWLEDGESURGE LEARNING SOLUTIONS I | | | SCAC4 |
| 19 | KLAR | K LINE AIR SERVICE (USA) INC | | | SCAC3 |
| 20 | KLASR | UAB Autoklasrida | | LT | TRAFFIC |
| 21 | KLAU | MINISTERIE VAN DEFENSIE | | NL | BIC |
| 22 | KLAX | H. Earl Clack Co. | 7/1930-7/1954; eliminated 10/1955 | | NAKINA |
| 23 | KLAX | H. Earl Clack Co. | 4/38-1/52 | | NRHS |
| 24 | KLAX | H. EARL CLACK CO. | | | PWRC |
| 25 | KLB | Air Mali International | IATA: XG, Callsign: Trans Mali, | RMM | AVCODES |
| 26 | KLB | Air Mali International | | | ICAO1 |
| 27 | KLB | Kriens-Luzern-Bahn | | CH | TRAFFIC |
| 28 | KLBB | KELLYS, BOB TOWING & RECOVERY SERVI | | | SCAC3 |
| 29 | KLBD | KALB, DAVID | | | SCAC3 |
| 30 | KLBD | KLASSENS, JAKE KITCHEN GALLERY | | | SCAC4 |
| 31 | KLBM | KM LOGISTICS LLC | | | SCAC4 |
| 32 | KLBN | KLEMME, F E | | | SCAC4 |
| 33 | KLBP | KIOLBASSA PROVISION COMPANY INC | | | SCAC4 |
| 34 | KLBR | K & L BROKERS INC | | | SCAC3 |
| 35 | KLBW | KLAMATH BASIN WAREHOUSE | | | SCAC3 |
| 36 | KLC | KLM Cityhopper B.V. (KLM Commuter) | IATA: WA, Callsign: City, IATA designator changed from HN / ICAO desigantor changed from NLM | NL | AVCODES |
| 37 | KLC | KLM Cityhopper | IATA: WA, Callsign: City, Name changed from KLM Cityhopper B.V. (KLM Commuter). IATA designator changed from HN / ICAO desigantor changed from NLM | NL | AVCODES |
| 38 | KLC | KLM Cityhopper | IATA: WA | | ICAO1 |
| 39 | KLC | KLM Cityhopper | | NL | TRAFFIC |
| 40 | KLCA | KLC TRANSPORTATION INC | | | SCAC4 |
| 41 | KLCB | KLC BROKERAGE INCORPORATED | | | SCAC4 |
| 42 | KLCC | K LOGISTICS CORP | | | SCAC4 |
| 43 | KLCD | KALESNIKOFF LUMBER CO LTD | | | SCAC4 |
| 44 | KLCE | KARIDAN LOGISTICS COMPANY LLC | | | SCAC4 |
| 45 | KLCG | KELLI-CHRISTOPHER TRUCKING INC | | | SCAC4 |
| 46 | KLCJ | KERYX LOGISTIX CORP | | | SCAC4 |
| 47 | KLCK | KLICKMAN, JAMES INC | | | SCAC4 |
| 48 | KLCL | KLCS LOGISTICS INC | | | SCAC4 |
| 49 | KLCN | KERKSIEK, LOREN C TRUCKING | | | SCAC4 |
| 50 | KLCO | KELCO TRANSPORTATION SERVICES INC | | | SCAC4 |
| 51 | KLCP | KOREA LINE CORPORATION | | | SCAC3 |
| 52 | KLCP | KOREA LINE CORPORATION | | | SCAC4 |
| 53 | KLCQ | KILCOYNE TRUCKING CO INC | | | SCAC3 |
| 54 | KLCQ | K & L TRUCKING INC | | | SCAC4 |
| 55 | KLCR | KELCOR TRUCKING INC | | | SCAC3 |
| 56 | KLCR | KELCOR TRUCKING INC | | | SCAC4 |
| 57 | KLCS | KLCS INC | | | SCAC4 |
| 58 | KLCU | CMA-CGM | | F | BIC |
| 59 | KLCU | IBJ LEASING COMPANY LIMITED | | | PWRC |
| 60 | KLCU | IBJ Leasing (Containerships Ltd) | | | RSRV |
| 61 | KLCU | ARIYUS IR PARTNERIAI T/A KURSIU LIN | | | SCAC4 |
| 62 | KLCV | KAYLA LOGISTICS CORP | | | SCAC4 |
| 63 | KLCY | KENNEBEC LUMBER COMPANY | | | SCAC4 |
| 64 | KLD | Air Klaipeda | Callsign: Air Klaopeda, | LT | AVCODES |
| 65 | KLD | Air Klaipeda | | | ICAO1 |
| 66 | KLDB | K & L DISTRIBUTORS INC | | | SCAC4 |
| 67 | KLDI | K L D COMPANY INC | | | SCAC3 |
| 68 | KLDK | KLEIN, DOYLE TRUCKING | | | SCAC4 |
| 69 | KLDN | KILDARE NAVIGATION S A | | | SCAC4 |
| 70 | KLDO | KALDO EXPRESS INC | | | SCAC4 |
| 71 | KLDS | KLAMATH DISPOSAL INC | | | SCAC3 |
| 72 | KLDT | KELDORN TRUCKING | | | SCAC3 |
| 73 | KLDU | KALKEDON INTERNATIONAL TRANSPORT & TRADE LTD | | TR | BIC |
| 74 | KLDV | KENLINE DISTRIBUTION SERVICES LTD | | | SCAC4 |
| 75 | KLE | Rusaero, Center For Civil Aviation Services | | RUS | AVCODES |
| 76 | KLE | Rusaero | | | ICAO1 |
| 77 | KLE | Fa. Klefenz GmbH, Gleisbau, Tief- und Straßenbau | | DE | VKM |
| 78 | KLED | KELLEY, ED TRUCKING | | | SCAC3 |
| 79 | KLEE | KILLEEN TRUCKING INC | | | SCAC3 |
| 80 | KLEG | K-LEE TRUCK LEASING | | | SCAC3 |
| 81 | KLEI | KELLEYS TRANSPORTATION INC | | | SCAC3 |
| 82 | KLEJ | KLEINJAN BROS | | | SCAC3 |
| 83 | KLEL | KALEELS EXPRESS, INC | | | SCAC3 |
| 84 | KLEL | KEHLER, DAVE | | | SCAC4 |
| 85 | KLEM | K-LINE EXPRESS | | | SCAC3 |
| 86 | KLEM | KLEIMAR LTD | | | SCAC4 |
| 87 | KLENK | Klenk Gleis und Tiefbau GmbH & Co KG | | DE | VKM |
| 88 | KLEO | KLENSKE BROTHERS TRUCKING | | | SCAC3 |
| 89 | KLEQ | KLEMM TANK LINES | | | SCAC3 |
| 90 | KLEQ | KLEMM TANK LINES | | | SCAC4 |
| 91 | KLES | KLEINSMITH TRUCKING | | | SCAC3 |
| 92 | KLET | KLEYSEN TRANSPORT LTD | | | SCAC3 |
| 93 | KLET | KLEYSEN GROUP LP | | | SCAC4 |
| 94 | KLEV | KLEVELANDS TOWING SERVICE | | | SCAC3 |
| 95 | KLEX | Kleysen Transport Ltd. | 7/2005 (not listed) | | NAKINA |
| 96 | KLEX | *KLEYSEN TRANSPORT LTD. | | | PWRC |
| 97 | KLEX | +KAYWAY INDUSTRIES INC. | | | PWRC |
| 98 | KLEX | KAYWAY INDUSTRIES INC | | | SCAC4 |
| 99 | KLEY | KELLEYTOWN TRANSPORTATION INC | | | SCAC4 |
| 100 | KLEY | Kley\'s Baumaschinen | | DE | VKM |
