List of reporting marks: U
# List of reporting marks: U

Note: Marks ending in U are for container owners; marks ending in X are not common carriers; marks ending in Z are for trailers without flanged wheels. All other marks are of common-carrier railroads.

## U

* UBTX - Union Camp Corporation
* UCCX - Union Carbide Canada, Ltd.
* UCEX - Union Electric Company
* UCFX - Union Carbide Corporation
* UCLX - Vulcan Minerals Company
* UCOX - Union Carbide Corporation
* UCPX - Essem Corporation
* UCR - Utah Coal Route
* UCRY - Utah Central Railway
* UELX - United Equipment Leasing Associates; Archer Daniels Midland
* UECZ - Union Elevator Co.
* UEEZ - Union Equity Elevator Co.
* UEFZ - Union Equity
* UFIX - Utility Fuels, Inc.
* UIWX - Riley Stoker Corporation
* UMP - Upper Merion and Plymouth Railroad
* UMPX - Upper Merion and Plymouth Leasing Company
* UNI - Unity Railways
* UNCX - Union Carbide Canada, Ltd.
* UNPX - Procor
* UNSX - Unitrain Services
* UO - Union Railroad (Oregon)
* UOCX - General American Transportation Corporation
* UP - Union Pacific Railroad
* UPAX - United Power Association
* UPB - Union Pacific Railroad
* UPFE - Pacific Fruit Express; Union Pacific Railroad
* UPM - Union Pacific Railroad (Milwaukee Road directed operations)
* UPOZ - United Parcel Service
* UPP - Union Pacific Railroad (passenger cars)
* UPRQ - Union Pacific Railroad End Of Train Devices
* UPRX - Union Pacific Fruit Express Company
* UPS - Union Pacific Railroad (slugs)
* UPSZ - United Parcel Service
* UPT - Union Pacific Railroad (fuel tenders)
* UPWZ - United Parcel Service
* UPX - Union Pearson Express
* UPY - Union Pacific Railroad (yard switchers)
* URDX - United States Steel
* URR - Union Railroad (Pittsburgh, Pennsylvania)
* URTX - Union Refrigerator Transit Line; General American Transportation Corporation
* URY - Union Railway of Memphis
* USAX - United States Army
* USBX - GE Rail Services
* USCX - William G. Simon
* USEX - Evans Railcar Leasing Company
* USFU - United States Air Force
* USGX - Union Sugar Company
* USIX - US Industrial Chemicals Company
* USLF - Burlington Northern Railroad
* USLX - Evans Railcar Leasing Company; GE Capital Railcar Services
* USNX - United States Navy
* USPX - US Plastics Corporation
* USRX - U.S. Railways, Inc.
* USSX - United States Steel
* USWX - USA Waste Services
* UTAH - Utah Railway
* UTAX - Utah Transit Authority (formerly assigned to United Transportation, Inc.)
* UTBX - Union Tank Car Company
* UTCX - Union Tank Car Company
* UTLX - Union Tank Car Company
* UTPX - Union Texas Petroleum Corporation
* UTR - Union Transportation
* UTTX - Trailer Train Company
