| 1 | TK | Turkish Airlines, Inc. | ICAO: THY, Callsign: Turkish, IATA Prefix: 235, Name changed from Turk Hava Yollari (Turkish Airlines). ICAO callsign changed from Turkair | TR | AVCODES |
| 2 | TK | Turk Hava Yollari (Turkish Airlines) | ICAO: THY, Callsign: Turkair, IATA Prefix: 235, Name changed to Turkish Airlines, Inc. ICAO callsign changed to Turkish | TR | AVCODES |
| 3 | TK | Tuskegee R.R. | 7/1954-4/1961 | | NAKINA |
| 4 | TK | Tuskegee R.R. | 10/57-4/61 | | NRHS |
| 5 | TK | TUSKEGEE RR | | | PWRC |
| 6 | TK | Cargorail - Transportes de Mercadorias, S.A. | | PT | VKM |
| 7 | TKA | Air Troika | Callsign: Troika, | RUS | AVCODES |
| 8 | TKA | Transliz Aviation (K) Ltd. | Callsign: Tourliz, | EAK | AVCODES |
| 9 | TKAB | T K TRUCKING LLC | | | SCAC4 |
| 10 | TKAB | Svenska Tågkompaniet AB | 1999 - | S | svenska-lok.se |
| 11 | TKAB | Svenska Tagkompaniet AB | 1999 - | S | TRAFFIC |
| 12 | TKAB | Svenska Tågkompagniet AB | | SE | VKM |
| 13 | TKAC | TRUCK AIR OF THE CAROLINAS, INC | | | SCAC1 |
| 14 | TKAE | TRU-KARE | | | SCAC4 |
| 15 | TKAF | TAKE ACTION NOW CORPORATION | | | SCAC4 |
| 16 | TKAG | TRUCK ACCESSORIES GROUP LLC | | | SCAC4 |
| 17 | TKAL | TRUCKALOCITY | | | SCAC4 |
| 18 | TKAM | THANKS A LOT | | | SCAC4 |
| 19 | TKANKO | Toyokanko | Part of the Keikyu Group | J | TRAFFIC |
| 20 | TKAQ | TRANSPORT KATO | | | SCAC4 |
| 21 | TKAR | TRUCK AMERICAN CARRIERS INC | | | SCAC4 |
| 22 | TKAS | TAKASE ADD SYSTEM INC | | | SCAC4 |
| 23 | TKBY | TREK BICYCLE CORP | | | SCAC4 |
| 24 | TKC | Tikal Jets, S.A. | IATA: A5, Callsign: Tikal, IATA designator changed to WU*. IATA designator changed from 2E* | GCA | AVCODES |
| 25 | TKC | Tikal Jets, S.A. | IATA: 2E, Callsign: Tikal, IATA designator changed to A5* | GCA | AVCODES |
| 26 | TKC | Tikal Jets, S.A. | IATA: WU, Callsign: Tikal, IATA designator changed to WU. IATA designator previously changed from 2E*, Then from A5* | GCA | AVCODES |
| 27 | TKC | Tikal Jets, S.A. | IATA: WU, Callsign: Tikal, Designator WU recalled by IATA. IATA designator changed from WU*. IATA designator previously changed from 2E*, Then from A5* | GCA | AVCODES |
| 28 | TKC | Tikal Jets, S.A. | Callsign: Tikal, Ceased operations. Designator WU recalled by IATA. IATA designator changed from WU*. IATA designator previously changed from 2E*, Then from A5* | GCA | AVCODES |
| 29 | TKC | THY Hava Kargo Tasimaciligi A.S. | Callsign: Trukish Cargo, | TR | AVCODES |
| 30 | TKC | Tikal Jets Airlines | | | ICAO1 |
| 31 | TKCB | TAIKO CARRIERS INC | | | SCAC4 |
| 32 | TKCC | TRUCKLOAD CARRIERS OF CHATTANOOGA L | | | SCAC4 |
| 33 | TKCD | TRANSTANK OF COLORADO LLC | | | SCAC4 |
| 34 | TKCE | TRUCK CITY EXPRESS LLC | | | SCAC4 |
| 35 | TKCH | THERMO KING | | | SCAC4 |
| 36 | TKCI | TRUCK-COURIER INC | | | SCAC4 |
| 37 | TKCP | TANKCON FRP INC | | | SCAC4 |
| 38 | TKCR | T K C TRANSPORT | | | SCAC4 |
| 39 | TKCS | Tiszakécske | | H | TRAFFIC |
| 40 | TKCT | THIESSEN LIVESTOCK | | | SCAC4 |
| 41 | TKCU | CONSERT S.R.L. | | I | BIC |
| 42 | TKCU | ABS PACIFIC | | | PWRC |
| 43 | TKCU | ABS Pacific (Concert) | | | RSRV |
| 44 | TKCU | CONSERT S R L | | | SCAC4 |
| 45 | TKCX | The Koster Co. | 8/1920 | | NAKINA |
| 46 | TKCX | Thiele Kaolin Co. | added 4/1968; 4/1970-7/2005; eliminated 4/2006 | | NAKINA |
| 47 | TKCX | Thiele Kaolin Co. | added 4/68; 4/70-7/2000 | | NRHS |
| 48 | TKCX | *KOSTER CO. | | | PWRC |
| 49 | TKCX | *THIELE KAOLIN COMPANY | | | PWRC |
| 50 | TKCX | Thiele Kaolin | | | RSRV |
| 51 | TKCY | TRUCKING COMPANY LLC, THE | | | SCAC4 |
| 52 | TKDT | TRAM K-D TRUCKING CORP | | | SCAC4 |
| 53 | TKDY | TECHNIMARK DE REYNOSA SA DE CV | | | SCAC4 |
| 54 | TKE | Trek Airways | Callsign: Trekair, | ZA | AVCODES |
| 55 | TKE | Trek Airways (Pty) Ltd. | IATA: JW, Callsign: Trekair, | ZA | AVCODES |
| 56 | TKE | Take Air Line | | | ICAO1 |
| 57 | TKEA | TRI TRUCK CENTRE INC | | | SCAC4 |
| 58 | TKED | THUNDER K ENTERPRISES LLC | | | SCAC4 |
| 59 | TKEG | TOLER, KENT TRUCKING | | | SCAC4 |
| 60 | TKEK | TEREK OIL | | | SCAC4 |
| 61 | TKEL | TURK ENTERPRISES LTD | | | SCAC4 |
| 62 | TKEM | TRANSPORTES KEMSA SA DE CV | | | SCAC4 |
| 63 | TKEN | Tennken R.R. Co., Inc. | added 4/1984; 1/1994-7/2005 | | NAKINA |
| 64 | TKEN | Tennken R.R. Co., Inc. | added 4/84; 1/94-7/2000 | | NRHS |
| 65 | TKEN | TENNKEN RAILROAD CO., INC. | | | PWRC |
| 66 | TKEN | Tennken Railroad | | | RSRV |
| 67 | TKEO | TRIPLE K EXPRESS COMPANY | | | SCAC4 |
| 68 | TKEP | TRUCKERS EXPRESS, INC. | | | SCAC1 |
| 69 | TKEQ | TRUCK LEASING OF BROOKLYN INC | | | SCAC4 |
| 70 | TKER | TESSENDERLO KERLEY INC | | | SCAC4 |
| 71 | TKES | TK EXPRESS LLC | | | SCAC4 |
| 72 | TKET | TRUCKING ENTERPRISES LLC | | | SCAC4 |
| 73 | TKEY | TURKEY HILL SUGARBUSH LTD | | | SCAC4 |
| 74 | TKEZ | T & K EVANS GRAIN, INC. | | | PWRC |
| 75 | TKF | UK Royal VIP Helicopter Flights | Callsign: Rainbow, ICAO designator changed from TQF. | GB | AVCODES |
| 76 | TKFG | TEAK FURNITURE GALLERY | | | SCAC4 |
| 77 | TKFI | TRUCK FREIGHT INTERNATIONAL LTD | | | SCAC4 |
| 78 | TKFN | TRIFISK MFG INC | | | SCAC4 |
| 79 | TKFO | THERMO KING FRESNO INC | | | SCAC4 |
| 80 | TKFR | TIMS TRUCKING | | | SCAC4 |
| 81 | TKFT | TASK FORCE TIPS INC | | | SCAC4 |
| 82 | TKGC | TANKSKIBSREDE | | | SCAC4 |
| 83 | TKGE | TRUCKGO & CO | | | SCAC4 |
| 84 | TKGFT | Thyssen Krupp Gft Gleistechnik Gmbh | | DE | VKM |
| 85 | TKGK | THANK GOD TRUCK INC | | | SCAC4 |
| 86 | TKGN | TECCO TRUCKING INC | | | SCAC4 |
| 87 | TKGO | TK MOLD & ENGINEERING INC | | | SCAC4 |
| 88 | TKGP | TRK GROUP, THE | | | SCAC4 |
| 89 | TKGQ | TEANECK LOGISTICS INC | | | SCAC4 |
| 90 | TKGR | TRUCKING R US INC | | | SCAC4 |
| 91 | TKHI | TURKISH EXPRESS LINE INC | | | SCAC4 |
| 92 | TKHT | TAKHAR TRANSPORTATION LLC | | | SCAC4 |
| 93 | TKHU | TRANSPORTKUHLUNG THERMO KING GMBH | | | SCAC4 |
| 94 | TKI | Turku Air Oy | Callsign: Turku Air, | FIN | AVCODES |
| 95 | TKIA | T & K NATIONWIDE TRUCKING INCORPROA | | | SCAC4 |
| 96 | TKIB | TRANS KNIGHTS INC | | | SCAC4 |
| 97 | TKIC | THOMAS, K INC | | | SCAC4 |
| 98 | TKID | TRUSSTEK INC | | | SCAC4 |
| 99 | TKIE | TRANSROCKIES INC | | | SCAC4 |
| 100 | TKIF | TICK INC | | | SCAC4 |
