| Abbreviation | Definition |
|---|---|
| UPRQ | Union Pacific Railroad |
| UPRR | Union Pacific Rail Road |
| UPRR | Union Pacific RailRoad |
| UPRU | Union Pacific Railroad |
| UPRU | Union Pacific Railroad Company |
| UPRX | Union Pacific Fruit Express |
| UPS | Union Pacific Railroad |
| UPSU | United Parcel Service |
| UPSZ | United Parcel Service |
| UPT | Union Pacific Railroad |
| UPTU | Union Pacific Bulktainer Service |
| UPUU | Union Pacific Bulktainer Service |
| UPWZ | United Parcel Service |
| UPX | Union Pearson Express |
| UPY | Union Pacific Railroad |
| UPY | Union Pacific Yard switch engine |
| UPZ | Union Pacific Railroad |
| UPZ | Union Pacific Railroad Company |
| URCS | Uniform Rail Costing System |
| URDX | Arch of Kentucky Incorporated |