| 1 | YM | Compass Airlines | ICAO: CYM, Callsign: Compair, Founded in 1990 ceased operations in 1991. Restarted operations in 1992 and finally ceased operations on 22 March 1993. | AUS | AVCODES |
| 2 | YM | Montenegro Airlines | ICAO: MGX, Callsign: Montair, IATA Prefix: 409, IATA designator changed from 1I | YU | AVCODES |
| 3 | YM | Dirac Aviation | ICAO: DAV, Callsign: Dirac, | F | AVCODES |
| 4 | YM | Montenegro Airlines | ICAO: MGX, Callsign: Montair, IATA Prefix: 409, IATA designator changed from 1I | SCG | AVCODES |
| 5 | YM | Montenegro Airlines | ICAO: MGX, Callsign: Montair, IATA Prefix: 409, Ceased operations in 25 December 2020. IATA designator changed from 1I | CG | AVCODES |
| 6 | YMBH | YMC TRANSPORT | | | SCAC4 |
| 7 | YMBU | P & O FERRYMASTERS LTD | | B | BIC |
| 8 | YMCI | YOUNG MANUFACTURING COMPANY INC | | | SCAC4 |
| 9 | YMCK | YMC TRUCKING | | | SCAC4 |
| 10 | YMCM | YOUNGS MARKET COMPANY | | | SCAC4 |
| 11 | YMCY | YURIMUNI COMPANY | | | SCAC4 |
| 12 | YMCZ | YANGMING MARINE TRANSPORT CORPORATION | | | PWRC |
| 13 | YMCZ | Yangming Marine Transport Corporation | | | RSRV |
| 14 | YMCZ | YANGMING MARINE TRANSPORT CORPORATI | | | SCAC4 |
| 15 | YMED | YAMASHI | | | SCAC4 |
| 16 | YMGT | Y M GROUP INC | | | SCAC4 |
| 17 | YMGU | CENTRE DE RENOVATION MARCEL DAGORT | | F | BIC |
| 18 | YMGU | Y M C G SRL | | | SCAC4 |
| 19 | YMIN | Yokohama Minatomirai Railway | | J | TRAFFIC |
| 20 | YMIP | YELLOW MOUNTAIN IMPORTS | | | SCAC4 |
| 21 | YMLU | YANG MING MARINE TRANSPORT CORP. | | RC | BIC |
| 22 | YMLU | YANGMING MARINE TRANSPORT CORPORATION | | | PWRC |
| 23 | YMLU | Yangming Marine Transport Corporation | | | RSRV |
| 24 | YMLU | YANGMING MARINE TRANSPORT CORP | | | SCAC1 |
| 25 | YMLU | YANG MING MARINE TRANSPORT CORP | | | SCAC4 |
| 26 | YMLZ | YANGMING MARINE TRANSPORT CORPORATION | | | PWRC |
| 27 | YMLZ | Yangming Marine Transport Corporation | | | RSRV |
| 28 | YMLZ | YANGMING MARINE TRANSPORT CORPORATI | | | SCAC4 |
| 29 | YMMU | YANG MING MARINE TRANSPORT CORP. | | RC | BIC |
| 30 | YMNS | YAMATO ENGINES SPECIALISTS 1990 LTD | | | SCAC4 |
| 31 | YMQZ | YELLOW MEDICAN QUARRY | | | PWRC |
| 32 | YMRJ | YAGOD, MAIER - REED, JON | | | SCAC4 |
| 33 | YMRU | YANMAR | | | SCAC4 |
| 34 | YMSP | YARMOUTH SEA PRODUCTS LTD | | | SCAC4 |
| 35 | YMTC | Y & M TRUCKING COMPANY | | | SCAC4 |
| 36 | YMVS | YUCCA MOVING & STORAGE INC | | | SCAC4 |
