| C0 | CLW | Centralwings | |
| C2 | ALU | Air Luxor STP | |
| C3 | IPR | 655 | Icar Airlines |
| C4 | COU | Airlines of Carriacou | |
| C4 | CGK | 094 | Click Airways |
| C4 | IMX | Zimex Aviation | |
| C6 | BHT | 116 | Bright Air |
| C7 | SCI | 424 | Special Cargo Airlines |
| C7 | UZS | 732 | Samarkand Airways |
| C8 | WDY | 488 | Chicago Express Airlines |
| C9 | RUS | 251 | Cirrus Airlines |
| C9 | CLA Air Transport | ||
| CA | CCA | 999 | Air China |
| CB | SAY | Suckling Airways | |
| CC | ABD | 318 | Air Atlanta Icelandic |
| CC | MCK | 374 | Macair Airlines |
| CD | LLR | 296 | Alliance Air |
| CE | CEX | Capitol Air Express | |
| CE | NTW | 567 | Nationwide Air |
| CF | CFP | Faucett Peruvian Airlines | |
| CH | BMJ | Bemidji Airlines | |
| CI | CAL | 297 | China Airlines |
| CJ | CBF | 782 | China Northern Airlines |
| CK | NDR | 600 | Andesmar Lineas Aereas |
| CK | CKK | 112 | China Cargo Airlines |
| CL | CLH | 683 | Lufthansa CityLine |
| CM | CMP | 230 | COPA Airlines |
| CN | 920 | Islands Nationair | |
| CO | COA | 005 | Continental Airlines |
| CP | CDN | 018 | Canadian Airlines International |
| CR | NHA | Air Nove | |
| CS | CMI | 596 | Continental Micronesia |
| CT | SFB | 551 | Air Sofia |
| CU | CUB | 136 | Cubana |
| CV | CLX | 172 | Cargolux Airlines |
| CW | MRS | 778 | Air Marshall Islands |
| CX | CPA | 160 | Cathay Pacific Airways |
| CY | CYP | 048 | Cyprus Airways |
| CZ | CSN | 784 | China Southern Airlines |
| CZ | CGH | Guizhou Airlines |