| 1 | OTC | Aero-Transportes de Carga, S.A. de C.V. | Callsign: Transporte Carga, | MEX | AVCODES |
| 2 | OTC | Air Travel Co., Ltd. | IATA: A6, Callsign: Air Travel, IATA Prefix: 389, Name changed from Yunnan Hong Tu Airlines Co., Ltd. ICAO designator changed from HTU. | PRC | AVCODES |
| 3 | OTCE | ONE TWO THREE (123) CAMP TRAILERS | | | SCAC4 |
| 4 | OTCG | ON-TIME CARTAGE INC | | | SCAC3 |
| 5 | OTCH | OTTUMWA COACHES INC | | | SCAC3 |
| 6 | OTCI | ON TIME CARRIERS INC | | | SCAC3 |
| 7 | OTCI | OLMSTED TRANSPORTATION CO INC | | | SCAC4 |
| 8 | OTCK | ORBIT TUNING CORP | | | SCAC4 |
| 9 | OTCL | OCEAN TRAMPING CO LTD | | | SCAC3 |
| 10 | OTCL | ONTRACC LOGISTICS INC | | | SCAC4 |
| 11 | OTCM | OWENS TRUCKING COMPANY | | | SCAC3 |
| 12 | OTCM | OT COMMUNICATIONS | | | SCAC4 |
| 13 | OTCN | OAK TANKER CORPORATION | | | SCAC4 |
| 14 | OTCO | Owensville Terminal Co., Inc. | 7/2000-7/2005 | | NAKINA |
| 15 | OTCO | Owensville Terminal Co., Inc. | Jul-00 | | NRHS |
| 16 | OTCO | OWENSVILLE TERMINAL COMPANY | | | PWRC |
| 17 | OTCO | Owensville Terminal | | | RSRV |
| 18 | OTCO | OWENSVILLE TERMINAL CO INC | | | SCAC4 |
| 19 | OTCP | OWENS, T C TRUCKING CO INC | | | SCAC3 |
| 20 | OTCQ | OSBORNE TRUCKING COMPANY | | | SCAC3 |
| 21 | OTCR | Oakdale Traction Corp. | 7/2005 | | NAKINA |
| 22 | OTCR | OAKDALE TRACTION CORPORATION | | | PWRC |
| 23 | OTCR | Oakdale Traction Corporation | | | RSRV |
| 24 | OTCR | OAKDALE TRACTION CORPORATION | | | SCAC4 |
| 25 | OTCT | OTC TRANSPORT CORPORATION | | | SCAC3 |
| 26 | OTCT | Oil Terminal Constanta | | RO | TRAFFIC |
| 27 | OTCV | OTC TRANSPORTATION SERVICES INC | | | SCAC4 |
| 28 | OTCY | OLYMPIC TRANSPORT COMPANY INC | | | SCAC3 |
