| Abbreviation | Definition |
|---|---|
| UPBZ | Union Pacific Railroad |
| UPBZ | Union Pacific Railroad Company |
| UPCU | USPCI Inc. |
| UPCU | USPCI Incorporated |
| UPCX | Laidlaw Environmental Services |
| UPCX | Laidlaw Environmental Services Incorporated |
| UPFE | Pacific Fruit Express (Union Pacific Railroad) |
| UPFE | Union Pacific Railroad Company |
| UPFU | Union Pacific Bulktainer Service |
| UPHU | Union Pacific Railroad |
| UPHU | Union Pacific Railroad Company |
| UPHZ | Union Pacific Railroad |
| UPM | Union Pacific Railroad |
| UPNZ | Union Pacific Railroad |
| UPNZ | Union Pacific Railroad Company |
| UPOZ | United Parcel Service |
| UPP | Union Pacific Railroad |
| UPP | Union Pacific Railroad Company - Passenger cars |
| UPR | Union Pacific Railroad |
| UPR | Union Pacific Railroad Company |