| Abbreviation | Definition |
|---|---|
| TZ | Tanzania |
| UA | Ukraine |
| UAA | Undeliverable As Addressed |
| UG | Uganda |
| UK | United Kingdom (Great Britain) |
| UM | US Minor Outlying Islands |
| UN | Unit |
| UPPR | Upper |
| UPS | United Parcel Service |
| UPU | Universal Postal Union |
| US | United States |
| USA | United States of America |
| USPS | United States Postal Service |
| UTF | Unable To Find |
| UY | Uruguay |
| VA | Vatican City State (Holy See) |
| VAL | Valley |
| VAL | Value Added Logistics |
| VAM | via air mail |
| VAP | Volume Arrival Profile |