| K2 | KGA | 758 | Kyrgyzstan Airlines |
| K2 | ELO | Eurolot | |
| K4 | KZA | 736 | Kazakhstan Airlines (Kazair) |
| K4 | CKS | 272 | Kalitta Air |
| K5 | JND | 225 | Air East Africa |
| K6 | KWZ | Khalifa Airways | |
| K7 | IKT | 840 | Sakha Avia |
| K8 | DCE | 559 | Dutch Caribbean Airlines |
| K8 | KLN | 097 | Kalingrad Air Enterprise |
| K9 | SGK | 470 | Skyward Aviation |
| K9 | ITM | 660 | Itapemirim Transportes Aereos |
| KA | HDA | 043 | Dragonair |
| KB | DRK | 787 | Druk Air |
| KC | KIC | 573 | Adagold Aviation |
| KD | KDA | 678 | Kendell Airlines |
| KE | KAL | 180 | Korean Air |
| KF | BLF | 142 | Blue1 |
| KG | GTV | 854 | Aerogaviota |
| KI | DHI | Adam Air | |
| KJ | LAJ | 436 | British Mediterranean Airways |
| KK | KKK | 610 | Atlasjet |
| KL | KLM | 074 | KLM Cargo |
| KL | KLC | KLM City Hopper | |
| KM | AMC | 643 | Air Malta |
| KO | QNK | Kabo Air | |
| KO | AER | Alaska Central Express | |
| KP | KIA | 538 | Kiwi International Airlines |
| KQ | KQA | 706 | Kenya Airways |
| KR | KHA | 798 | Kitty Hawk Aircargo |
| KR | KMZ | Comores Aviation | |
| KS | PEN | 339 | Penair |
| KT | CKT | Caledonian Airways | |
| KT | TLT | Turtle Airways | |
| KU | KAC | 229 | Kuwait Airways |
| KV | MVD | Kavminvodyavia | |
| KW | PXA | 388 | Pan American World Airways |
| KX | CAY | 378 | Cayman Airways |
| KY | EQL | 980 | Air Sao Tome e Principe |
| KZ | NCA | 933 | Nippon Cargo Airlines |
| KZ | LER | 722 | Linea Aerea |