| Abbreviation | Definition |
|---|---|
| TH | Thailand |
| TJ | Tajikistan |
| TK | Tokelau |
| TM | Turkmenistan |
| TMS | Transportation Management System |
| TN | Tunisia |
| TO | Tonga |
| TOFC | Trailer-On-FlatCar |
| TP | East Timor |
| TPMR | Third Party Mail Relay |
| TPO | Transfer Post Office |
| TPO | Travelling Post Office |
| TQM | Total Quality Management |
| TR | Turkey |
| TRL | TRaiL |
| TRLR | Trailer |
| TT | Trinidad and Tobago |
| TTC | Technical Training Center |
| TV | Tuvalu |
| TW | Taiwan |