| 1 | TTN | Lip-Avia | Callsign: Zavod, | KZ | AVCODES |
| 2 | TTN | Highland Express | | GB | AVCODES |
| 3 | TTN | Absolute Flight Services (Pty) Ltd. | Callsign: Titanium, | ZA | AVCODES |
| 4 | TTNB | TRUST, THE COMPANY OF THE | | | SCAC4 |
| 5 | TTNC | TURNER & TURNER TRUCKING LLC | | | SCAC4 |
| 6 | TTNF | TRAILER TRANSFER | | | SCAC4 |
| 7 | TTNI | TRIAD TRANSPORT INC | | | SCAC4 |
| 8 | TTNN | TRANSPORTES TRANSCONTINENTALES SA D | | | SCAC4 |
| 9 | TTNO | TURNER TRANSPORT LTD | | | SCAC4 |
| 10 | TTNP | TITAN TRANSPORT LTD | | | SCAC4 |
| 11 | TTNR | TWO TWO NINE ONE ONE SIX THREE (229 | | | SCAC4 |
| 12 | TTNS | TITAN SERVICES OF OKLAHOMA LLC | | | SCAC4 |
| 13 | TTNT | TITAN TRANSPORTATION INC | | | SCAC4 |
| 14 | TTNU | TRITON CONTAINER INTERNATIONAL LTD | | BM | BIC |
| 15 | TTNU | Triton Container International | | | RSRV |
| 16 | TTNU | TRITON CONTAINER INTERNATIONAL LTD | | | SCAC4 |
| 17 | TTNV | TRANSNET INC | | | SCAC4 |
| 18 | TTNX | Texas Tanning Extract Co. | 4/1947-1/1952 | | NAKINA |
| 19 | TTNX | Trailer Train Co. | added 5/1983; eliminated 1/1992 | | NAKINA |
| 20 | TTNX | TTX Co. | added 1/1992; 1/1994-7/2005 | | NAKINA |
| 21 | TTNX | Trailer Train Co. (flat cars equipped with bi-level auto racks without end doors and with or without roof panels) | added 5/1983; 7/1985 | | NAKINA |
| 22 | TTNX | Trailer Train Co. (not defined) | 10/1991 | | NAKINA |
| 23 | TTNX | TTX Co. (flat car equipped with fully enclosed unilevel rack furnished by participants. Used for loading large trucks) | 1/1992-1/1994 | | NAKINA |
| 24 | TTNX | Texas Tanning Extract Co. | Jan-52 | | NRHS |
| 25 | TTNX | Trailer Train Co. | added 5/83; eliminated 1/92 | | NRHS |
| 26 | TTNX | TTX Co. | added 1/92; 1/94 | | NRHS |
| 27 | TTNX | *TEXAS TANNING EXTRACT CO. | | | PWRC |
| 28 | TTNX | +TTX COMPANY {TRAILER TRAIN COMPANY} | | | PWRC |
| 29 | TTNX | Trailer Train (TTX Corporation) | | | RSRV |
| 30 | TTNX | TTX COMPANY | | | SCAC4 |
| 31 | TTNZ | FLEXI-VAN LEASING INC | | | SCAC4 |
