| IAC | IC | 058 | Indian Airlines |
| IAW | IA | 073 | Iraqi Airways |
| IBB | NT | 474 | Binter Canarias |
| IBE | IB | 075 | Iberia |
| IBX | FW | Ibex Airlines | |
| ICB | HH | 652 | Islandsflug |
| ICE | FI | 108 | Icelandair Cargo |
| ICL | 5C | 700 | CAL Cargo Airlines |
| ICN | Inter-Canadian (Canadian Partner) | ||
| ICT | RS | Intercontinental de Aviacion | |
| IDF | Iron Dragon Fly | ||
| IFL | Corporate Express | ||
| IFT | Interflight | ||
| IGO | 6E | IndiGo Airlines | |
| IKA | GI | 420 | Itek Air |
| IKR | Ikaros Fly | ||
| IKT | K7 | 840 | Sakha Avia |
| ILN | D6 | 625 | Inter-Aviation Services |
| ILP | IO | ILPO Aruba Cargo | |
| ILV | Ilavia Airlines | ||
| IML | Maya Island Air | ||
| IMR | Impulse Aero | ||
| IMT | Imtrec Aviation | ||
| IMX | C4 | Zimex Aviation | |
| INL | Intal Avia | ||
| INS | Informtrans-Avia | ||
| INV | Inversija | ||
| INX | 6K | Inter Airlines | |
| IOS | 5Y | Isles of Scilly Skybus | |
| IPL | Impala Air | ||
| IPR | C3 | 655 | Icar Airlines |
| IRA | IR | 096 | Iran Air |
| IRC | EP | 815 | Iran Aseman Airlines |
| IRK | Y9 | 780 | Kish Air |
| IRM | W5 | 537 | Mahan Air |
| IRO | CSA Air | ||
| IRP | 2F | 010 | Payam (IPTAS) |
| IRQ | Qeshm Air | ||
| IRR | Tara Airlines | ||
| IRT | IQ | 614 | Interot Airways |
| IRZ | Saha Airlines | ||
| ISK | 3L | Intersky | |
| ISL | X9 | City Star Airlines | |
| ISP | Gosnii | ||
| ISR | 6H | 818 | Israir |
| ISS | IG | 191 | Meridiana |
| IST | IL | Istanbul Airlines | |
| ISV | WC | 282 | Islena Airlines |
| ITB | Q9 | 151 | Interbrasil Star |
| ITF | IT | 279 | Air Inter |
| ITM | K9 | 660 | Itapemirim Transportes Aereos |
| ITT | Inter Trans Air | ||
| ITX | IK | 166 | Imair Airline |
| IVN | Ivan Air | ||
| IWD | Iberworld | ||
| IYE | IY | 635 | Yemenia Airways |