| 1 | KLA | Air Lithuania | IATA: TT, Callsign: Kaunas, IATA Prefix: 843, | LT | AVCODES |
| 2 | KLA | SKA SA Aircraft Leasing (Pty) Ltd | | ZA | AVCODES |
| 3 | KLA | Air Lithuania | IATA: TT | | ICAO1 |
| 4 | KLA | Koniklije Landmacht | | NL | TRAFFIC |
| 5 | KLAB | KOLA BUILDING MOVERS LTD | | | SCAC4 |
| 6 | KLAC | KLASSIC EXPRESS INC | | | SCAC4 |
| 7 | KLAE | K-LINE AMERICA | | | SCAC3 |
| 8 | KLAF | KLEINS MOVING & STORAGE INC | | | SCAC3 |
| 9 | KLAF | KLEINS MOVING & STORAGE INC | | | SCAC4 |
| 10 | KLAI | KEONI LINES LLC | | | SCAC4 |
| 11 | KLAL | K & L AUTOMOTIVE | | | SCAC4 |
| 12 | KLAM | KLAMATH MOVING & STORAGE CO | | | SCAC3 |
| 13 | KLAM | KLAMATH MOVING & STORAGE COMPANY IN | | | SCAC4 |
| 14 | KLAP | KLAPEC EXPRESS INC | | | SCAC4 |
| 15 | KLAP | UAB Klaipedos autobusu parkas | City: Klaipeda | LT | TRAFFIC |
| 16 | KLAQ | KNOWLEDGESURGE LEARNING SOLUTIONS I | | | SCAC4 |
| 17 | KLAR | K LINE AIR SERVICE (USA) INC | | | SCAC3 |
| 18 | KLASR | UAB Autoklasrida | | LT | TRAFFIC |
| 19 | KLAU | MINISTERIE VAN DEFENSIE | | NL | BIC |
| 20 | KLAX | H. Earl Clack Co. | 7/1930-7/1954; eliminated 10/1955 | | NAKINA |
| 21 | KLAX | H. Earl Clack Co. | 4/38-1/52 | | NRHS |
| 22 | KLAX | H. EARL CLACK CO. | | | PWRC |
