| 1 | TEC | TEA Cyprus Ltd. | Callsign: Teak, Ceased operations. | CY | AVCODES |
| 2 | TEC | ADI Shuttle Group, LLC | Callsign: Techjet, | USA | AVCODES |
| 3 | TEC | TOTEM COACHES INC | | | SCAC4 |
| 4 | TEC | Société Régionale Wallonne du Transport | 5 regional public transport companies branded as TEC or "Transport En Commun" | B | TRAFFIC |
| 5 | TECA | TEMPO CARTAGE INC | | | SCAC3 |
| 6 | TECA | TECATE LOGISTICS LLC | | | SCAC4 |
| 7 | TECB | TRIPLE EAGLE CONTAINER LINE LTD | | | SCAC4 |
| 8 | TECC | TRANS-ECONOWAY CARTAGE INC | | | SCAC3 |
| 9 | TECC | TECHNICO INC | | | SCAC4 |
| 10 | TECD | TERMINAL CONSOLIDATION COMPANY | | | SCAC3 |
| 11 | TECD | TERMINAL CONSOLIDATION COMPANY | | | SCAC4 |
| 12 | TECE | TECE TRUCKING INC | | | SCAC4 |
| 13 | TECF | TEC TRANSPORT SYSTEMS INC | | | SCAC3 |
| 14 | TECF | TECNOSTEEL SA DE CV | | | SCAC4 |
| 15 | TECG | TEAM CARRIERS INC (A DIV OF MANITOU | | | SCAC3 |
| 16 | TECHAI | TEC Hainaut | The bus network of the Hainaut Territorial Directorate is part of the Walloon Transport Operator (formerly SRWT) | B | TRAFFIC |
| 17 | TECI | TECH LOGISTICS INC | | | SCAC4 |
| 18 | TECK | Tecklenburger Nordbahn | Real: TN | D | TRAFFIC |
| 19 | TECL | TEC LEASING | | | SCAC3 |
| 20 | TECL | TECHNICAL LOGISTICS CORPORATION | | | SCAC4 |
| 21 | TECLV | TEC Liège-Verviers | | B | TRAFFIC |
| 22 | TECM | TERRA-COMMERCIAL TRANSPORT | | | SCAC3 |
| 23 | TECN | TECHNOLOGY DISTRIBUTION SYSTEM, INC | | | SCAC3 |
| 24 | TECNOFER | Tecnofer s.r.l. | | I | TRAFFIC |
| 25 | TECO | COPAC RAIL [CONTINENTAL PACIFIC RWY.; TEAMO-TACOMA RAILROAD] | | | PWRC |
| 26 | TECO | Teamo-Tacoma Railroad (Lincoln Pacific Railway) | | | RSRV |
| 27 | TECO | TERMICOLD CORPORATION | | | SCAC3 |
| 28 | TECO | TERMICOLD CORPORATION | | | SCAC4 |
| 29 | TECP | TENENBAUM, A COMPANY INC | | | SCAC3 |
| 30 | TECQ | TERMINAL CARTAGE CO | | | SCAC3 |
| 31 | TECQ | TR ELECTRONIC | | | SCAC4 |
| 32 | TECR | TECREP | | | SCAC3 |
| 33 | TECS | TEMPCO CONTRACTING & SUPPLY CORP | | | SCAC3 |
| 34 | TECS | TecSol | | A | TRAFFIC |
| 35 | TECSA | | | E | TRAFFIC |
| 36 | TECSA | TECSA EMPRESA CONSTRUCTORA, S.A. | | ES | VKM |
| 37 | TECT | TECUMSEH TRANSFER | | | SCAC3 |
| 38 | TECT | TECH TRAILERS/AUTO EXCESSORIES (DIV | | | SCAC4 |
| 39 | TECU | TECHNOLOGY INDUSTRIAL GASES PRODUCTION CO | | KWT | BIC |
| 40 | TECW | TECHMEIER, WALTER C | | | SCAC3 |
| 41 | TECX | TEC Terminals, Inc. | added 7/1970; eliminated 1/1973 | | NAKINA |
| 42 | TECX | Robertson Terminals, Inc. | added 1/1973; 1/1975; eliminated 1/1977 | | NAKINA |
| 43 | TECX | Paktank Gulfcoast, Inc. | added 1/1977; eliminated 10/1977 | | NAKINA |
| 44 | TECX | Texas Crushed Stone Co. | added 10/1982; eliminated 5/1983; 1/1994 (not listed) | | NAKINA |
| 45 | TECX | TEC Terminals, Inc. | added 7/70 | | NRHS |
| 46 | TECX | Robertson Terminals, Inc. | 1/75; eliminated 1/77 | | NRHS |
| 47 | TECX | Paktank Gulfcoast, Inc. | added 1/77 | | NRHS |
| 48 | TECX | Texas Crushed Stone Co. | added 10/82; eliminated 5/83; 1/94 | | NRHS |
| 49 | TECX | *PAKTANK GULFCOAST, INC. [ROBERTSON TERMINALS, INC.; TEC TERMINALS, INC.] | | | PWRC |
| 50 | TECX | *TEXAS CRUSHED STONE INC. | | | PWRC |
| 51 | TECX | Texas Crushed Stone | | | RSRV |
| 52 | TECYR | TECYR CONSTRUCCIONES Y REPARACIONES, S.A. | | ES | VKM |
| 53 | TECYR | TECYR CONSTRUCCIONES Y REPARACIONES, S.A. | | ES | VKM |
| 54 | TECZW | TECKLENBORG GmbH & Co. KG | | DE | VKM |
