| 2601 | MELX | Sunbelt Cement, Inc. | added 4/1991; eliminated 7/1991; 1/1994 (not listed); 7/2000 (not listed); added 10/2000; eliminated 10/2002 | | NAKINA |
| 2602 | MELX | Melwire Inc. | added 10/1985; eliminated 4/1991 | | NAKINA |
| 2603 | MELX | Milwaukee Electric Ry. & Light Co. | 8/1920 | | NAKINA |
| 2604 | MELX | Melwire Inc. | eliminated 4/91 | | NRHS |
| 2605 | MELX | Sunbelt Cement, Inc. | added 4/91; eliminated 7/91; 1/94-7/2000; added 10/2000 | | NRHS |
| 2606 | MELX | *MILWAUKEE ELECTRIC RWY. & LIGHT CO. | | | PWRC |
| 2607 | MELX | *MELWIRE INC. | | | PWRC |
| 2608 | MELX | *SUNBELT CEMENT, INC. | | | PWRC |
| 2609 | MELX | Melwire Inc. (Sunbelt Cement) | | | RSRV |
| 2610 | MELZ | MILLIGAN ELEVATOR | | | PWRC |
| 2611 | MEM | Mediterranean Air Ambulance, S.L. | Callsign: Meditair, | E | AVCODES |
| 2612 | MEM | LLC Aircompany MERIDIAN | Callsign: Meridian Cherry, | UA | AVCODES |
| 2613 | MEM | Meridian Limited | | | ICAO1 |
| 2614 | MEM | Museumseisenbahn Minden e.V. | Minden | D | privat-bahn.de |
| 2615 | MEM | Museums-Eisenbahn Minden e.V | | DE | VKM |
| 2616 | MEMA | MEGAMATS | | | SCAC4 |
| 2617 | MEMC | MARATHON ELECTRIC MFG CORP | | | SCAC4 |
| 2618 | MEME | ME MARITTIMA EMILIANA S A P | | | SCAC4 |
| 2619 | MEMF | MIRANDA ELIZONDO, MARVA LAURA | | | SCAC4 |
| 2620 | MEMI | METRIC MOLD (1983) INC | | | SCAC4 |
| 2621 | MEMN | METRO MOVING SERVICES INC | | | SCAC4 |
| 2622 | MEMQ | MESA SYSTEMS INC | | | SCAC4 |
| 2623 | MEMR | MEDMAR | | | SCAC4 |
| 2624 | MEMU | MELKWEG / FRITOM BV | | NL | BIC |
| 2625 | MEMU | MELKWEG MULLER COMBINATIE BV | | | SCAC4 |
| 2626 | MEMZ | MERIDIAN MINERALS | | | PWRC |
| 2627 | MEN | MAE Aircraft Management WLL | IATA: MA, Callsign: Rahal, IATA Prefix: 723, | BRN | AVCODES |
| 2628 | MEN | Minskavia | IATA: 4M, Callsign: Minsk, Designator 4M recalled by IATA | BY | AVCODES |
| 2629 | MENA | Carrozzeria Menarini | | I | TRAFFIC |
| 2630 | MENC | MENDEZ TRUCKING | | | SCAC4 |
| 2631 | MEND | MENDIVIL CHAN, CESAR | | | SCAC4 |
| 2632 | MEND | Mendip Rail Limited | Real: MRL | GB | TRAFFIC |
| 2633 | MENE | MITCHELL ENTERPRIZE | | | SCAC4 |
| 2634 | MENH | MSK ENTERPRISES | | | SCAC4 |
| 2635 | MENM | MENSAJE | | | SCAC4 |
| 2636 | MENP | MENASHA TRANSPORT, INC | | | SCAC1 |
| 2637 | MENQ | MONTES, ENRIQUE R | | | SCAC4 |
| 2638 | MENT | ENTERPRISES MCPELL INC | | | SCAC4 |
| 2639 | MENU | MENADIONA, S.L. | | E | BIC |
| 2640 | MENV | MATRIX ENVIRONMENTAL SOLUTIONS LTD | | | SCAC4 |
| 2641 | MENY | MATES, INC | | | SCAC1 |
| 2642 | MEO | Bohnstedt Petersen Og Dyrberg A/S | Callsign: Metro Airways, Designator BE recalled by IATA | DK | AVCODES |
| 2643 | MEO | Bohnstedt Petersen Og Dyrberg A/S | IATA: BE, Callsign: Metro Airways, | DK | AVCODES |
| 2644 | MEOD | METRO DIRECT INC | | | SCAC4 |
| 2645 | MEOF | METOYER FARMS LLC | | | SCAC4 |
| 2646 | MEOG | MACK TRANSPORT INC | | | SCAC4 |
| 2647 | MEOL | METRO LEASING CO | | | SCAC4 |
| 2648 | MEOM | MERTENS OIL CO | | | SCAC4 |
| 2649 | MEON | METRO INTERSTATE INC | | | SCAC4 |
| 2650 | MEOP | METRO TRANSPORTATION | | | SCAC4 |
| 2651 | MEOQ | MID-EASTERN OIL CO INC | | | SCAC4 |
| 2652 | MEOR | METRO-NORTH COMMUTER RAILROAD | | | SCAC4 |
| 2653 | MEOX | MUNICH ELEV. OIL CO. | | | PWRC |
| 2654 | MEOX | MUNICH ELEVATOR & OIL CO | | | SCAC4 |
| 2655 | MEOY | MERIT OIL CO | | | SCAC4 |
| 2656 | MEP | Midwest Express Airlines, Inc. | IATA: YX, Callsign: Midex, IATA Prefix: 453, Name changed to Midwest Airlines, Inc. w.e.f. 28 February 2003. | USA | AVCODES |
| 2657 | MEP | Midwest Airlines, Inc. | IATA: YX, Callsign: Midex, IATA Prefix: 453, Name changed to Republic Airlines, Inc d/b/a Midwest Airlines, Inc. Name changed from Midwest Express Airlines, Inc. w.e.f. 28 February 2003. | USA | AVCODES |
| 2658 | MEP | Republic Airlines, Inc d/b/a Midwest Airlines, Inc. | IATA: YX, Callsign: Midex, IATA Prefix: 453, Merged into Frontier Airlines w.e.f. 03 November 2010. Name changed from Midwest Airlines, Inc. w.e.f. 23 June 2009. | USA | AVCODES |
| 2659 | MEP | Midwest Airlines | IATA: YX | | ICAO1 |
| 2660 | MEPB | METRO PAPER BOX LIMITED | | | SCAC4 |
| 2661 | MEPD | MITSUBISHI ELECTRIC POWER PRODUCTS | | | SCAC4 |
| 2662 | MEPH | MERCIER, PHILIPPE (1994) INC | | | SCAC4 |
| 2663 | MEPI | MCDONALD TRANSPORTATION INC | | | SCAC4 |
| 2664 | MEPJ | MSC EXPEDITOR INC | | | SCAC4 |
| 2665 | MEPK | MRN ENTERPRISES INC | | | SCAC4 |
| 2666 | MEPM | MARCO ENTERPRISES LLC | | | SCAC4 |
| 2667 | MEPQ | MERRITT ENERGY PARTNERS | | | SCAC4 |
| 2668 | MEPR | MITCHEL ENTERPRISES CORPORATION | | | SCAC4 |
| 2669 | MEPS | MEP LOGISTICS | | | SCAC4 |
| 2670 | MEPT | M E P TRUCKING | | | SCAC4 |
| 2671 | MEPV | MOLDURAS EL PURRUN SA DE CV | | | SCAC4 |
| 2672 | MEPW | MARITIME EQUITY PARTNERS LLC | | | SCAC4 |
| 2673 | MEPX | McGraw-Edison Co. | added 4/1969; 4/1970-1/1980; eliminated 10/1993; 1/1994-7/2005 (not listed) | | NAKINA |
| 2674 | MEPX | McGraw-Edison Co. | added 4/69; 4/70-1/80; eliminated 10/93; 1/94-7/2000 | | NRHS |
| 2675 | MEPX | *MEAD PAPER COMPANY | | | PWRC |
| 2676 | MEPX | +McGRAW-EDISON COMPANY | | | PWRC |
| 2677 | MEPX | McGraw-Edison | | | RSRV |
| 2678 | MEPX | MC GRAW-EDISON COMPANY | | | SCAC4 |
| 2679 | MEQB | MORRISON EQUIPMENT | | | SCAC4 |
| 2680 | MEQN | MEDICAL EQUIPMENT CONTRACTORS INC | | | SCAC4 |
| 2681 | MEQR | MEDICAL EQUIPMENT CORPORATION | | | SCAC4 |
| 2682 | MEQT | MATTOS EQUIPMENT TRANSPORT | | | SCAC1 |
| 2683 | MEQU | MILESTONE EQUIPMENT CORPORATION | | | SCAC4 |
| 2684 | MEQY | MINTO ENERGY CORPORATION | | | SCAC4 |
| 2685 | MEQZ | MILESTONE EQUIPMENT CORPORATION | | | SCAC4 |
| 2686 | MER | Methow Aviation, Inc. | Callsign: Methow, | USA | AVCODES |
| 2687 | MER | Methow Aviation | | | ICAO1 |
| 2688 | MER | Macquarie European Rail Limited (Luxembourg Branch) | | LU | VKM |
| 2689 | MERA | MERADA TRANSPORTATION LTD | | | SCAC4 |
| 2690 | MERA | Metrans Rail | Real: MT | CZ | TRAFFIC |
| 2691 | MERCER | Mercer Metro | | USA | TRAFFIC |
| 2692 | MERE | MULTI EXTERIORS & RENOVATIONS USA I | | | SCAC4 |
| 2693 | MERF | MERKS FARMS LTD | | | SCAC4 |
| 2694 | MERK | MERRICK ENGINEERING INC | | | SCAC4 |
| 2695 | MERN | MERIDIAN OPERATIONS LLC | | | SCAC4 |
| 2696 | MERP | MERIT TRANSPORT LIMITED | | | SCAC4 |
| 2697 | MERQ | MEDICAL EDUCATION & RESEARCH INSTIT | | | SCAC4 |
| 2698 | MERR | Morristown & Erie Ry. Inc. d/b/a Maine Eastern R.R. | added 1/2004; eliminated 7/2004; 7/2005 | | NAKINA |
| 2699 | MERR | MORRISTOWN & ERIE RWY. INC. d/b/a MAINE EASTERN RAILROAD | | | PWRC |
| 2700 | MERR | Maine Eastern Railroad | | | RSRV |
