| 1801 | USBX | US Borax & Chemical (CIT Group) | | | RSRV |
| 1802 | USBX | CIT GROUP/CAPITAL FINANCE INC, THE | | | SCAC4 |
| 1803 | USC | US Check Airlines | Callsign: Starcheck, Name changed to AirNet Systems, Inc. | USA | AVCODES |
| 1804 | USC | AirNet Systems, Inc. | Callsign: Starcheck, Name changed to Airnet II, LLC. Name changed from US Check Airlines, | USA | AVCODES |
| 1805 | USC | AirNet II, LLC | Callsign: Star Check, Name changed from AirNet Systems, Inc. Name changed from US Check Airlines, | USA | AVCODES |
| 1806 | USC | US Check Airlines | | | ICAO1 |
| 1807 | USC | UNITED STOCKYARDS CORP. | | | PWRC |
| 1808 | USCC | USCS CHEMICAL CHARTERING LLC | | | SCAC4 |
| 1809 | USCE | US OCEAN LLC | | | SCAC4 |
| 1810 | USCF | USCA FORWARDING - SEABELL EXPRESS I | | | SCAC4 |
| 1811 | USCG | USC GROUP INC. | | | SCAC1 |
| 1812 | USCG | U S PORT SERVICES INC | | | SCAC4 |
| 1813 | USCG | United States Coast Guard | | USA | TRAFFIC |
| 1814 | USCH | USS CHARTERING LLC | | | SCAC4 |
| 1815 | USCI | USCT INC | | | SCAC4 |
| 1816 | USCJ | USG SERVICES LLC | | | SCAC4 |
| 1817 | USCK | US PACIFIC TRANSPORT INC | | | SCAC4 |
| 1818 | USCP | UNITED STATES COLD STORAGE INC | | | SCAC4 |
| 1819 | USCR | UNITY SHIPPING CO LTD | | | SCAC4 |
| 1820 | USCT | U S CONTRACT TRUCKING INC | | | SCAC4 |
| 1821 | USCU | UNION STEAM SHIP CO. OF NZ LTD. | | | PWRC |
| 1822 | USCU | Union Steam Ship of NZ | | | RSRV |
| 1823 | USCU | CP SHIPS | | | SCAC4 |
| 1824 | USCV | UNITRANS | | | SCAC4 |
| 1825 | USCX | United States Coal & Coke Co. | 8/1920-7/1932 | | NAKINA |
| 1826 | USCX | United States Tank Car Corp. | added 10/1972; eliminated 1/1975 | | NAKINA |
| 1827 | USCX | William G. Simon, Trustee | added 1/1975; 1/1975; eliminated 7/1975 | | NAKINA |
| 1828 | USCX | William G. Simon | added 7/1975; 1/1980-7/2000; eliminated 7/2003 | | NAKINA |
| 1829 | USCX | United States Tank Car Corp. | added 10/72; eliminated 1/75 | | NRHS |
| 1830 | USCX | William G. Simon, Trustee | added 1/75; 1/75; eliminated 7/75 | | NRHS |
| 1831 | USCX | William G. Simon | added 7/75; 1/80-7/2000 | | NRHS |
| 1832 | USCX | WILLIAM G. SIMON TANK CAR MANAGEMENT [UNITED STATES TANK CAR CORP.; UNITED STATES COAL & COKE CO.] | | | PWRC |
| 1833 | USCX | William G. Simon | | | RSRV |
| 1834 | USCY | USACYC TRANSPORT | | | SCAC4 |
| 1835 | USCZ | U. S. REDUCTION COMPANY, INC. | | | PWRC |
| 1836 | USDI | U S TRANSPORT INC | | | SCAC4 |
| 1837 | USDK | USCOM SD INC | | | SCAC4 |
| 1838 | USDL | UNIVAN SHIP MANAGEMENT LIMITED | | | SCAC4 |
| 1839 | USDO | USDUONG INC | | | SCAC4 |
| 1840 | USDS | USF DISTRIBUTION SERVICES, INC | | | SCAC1 |
| 1841 | USDU | UNISPEED LTD | | | SCAC4 |
| 1842 | USDV | U S DELIVERY, J. White, INC | | | SCAC1 |
| 1843 | USDY | US DELIVERY | | | SCAC4 |
| 1844 | USEB | U | | | SCAC4 |
| 1845 | USEC | U S EXPRESS INC | | | SCAC4 |
| 1846 | USED | U S E D | | | SCAC4 |
| 1847 | USEE | U S EXPRESS INC | | | SCAC4 |
| 1848 | USEG | U S EXPEDITING & LOGISTICS LLC | | | SCAC4 |
| 1849 | USEH | US EXPRESS FREIGHT SYSTEMS INC | | | SCAC4 |
| 1850 | USEI | U S EXPRESS INC | | | SCAC4 |
| 1851 | USEP | U S EXPRESS INC | | | SCAC4 |
| 1852 | USES | U S EXPRESS CO | | | SCAC4 |
| 1853 | USEX | United States Railway Equipment Co. | added 4/1955; 10/1957-1/1975; eliminated 7/1979 | | NAKINA |
| 1854 | USEX | United States Leasing Co. | added 7/1979 | | NAKINA |
| 1855 | USEX | United States Railway Leasing Co. | 1/1980; eliminated 10/1980 | | NAKINA |
| 1856 | USEX | Evans Railcar Leasing Co. | added 10/1980; eliminated 4/1988 | | NAKINA |
| 1857 | USEX | Itel Rail Corp. | added 4/1988; eliminated 10/1992 | | NAKINA |
| 1858 | USEX | General Electric Railcar Services Corp. | added 10/1992; 1/1994; eliminated 1/2000 | | NAKINA |
| 1859 | USEX | General Electric Rail Services Corp. | added 1/2000; 7/2000-7/2005 | | NAKINA |
| 1860 | USEX | United States Railway Equipment Co. | added 4/55; 10/57-1/75; eliminated 7/79 | | NRHS |
| 1861 | USEX | United States Leasing Co. | added 7/79 | | NRHS |
| 1862 | USEX | United States Railway Leasing Co. | 1/80; eliminated 10/80 | | NRHS |
| 1863 | USEX | Evans Railcar Leasing Co. | added 10/80; eliminated 4/88 | | NRHS |
| 1864 | USEX | Itel Rail Corp. | added 4/88; eliminated 10/92 | | NRHS |
| 1865 | USEX | General Electric Railcar Services Corp. | added 10/92; 1/94; eliminated 1/2000 | | NRHS |
| 1866 | USEX | General Electric Rail Services Corp. | added 1/2000; 7/2000 | | NRHS |
| 1867 | USEX | (NATX) GEN. ELECTRIC RAIL SERVICES CORP. [ITEL RAIL CORP.; EVANS RAILCAR LEASING CO.; UNITED STATES RAILWAY LEASING CO.] | | | PWRC |
| 1868 | USEX | Evans Railcar Leasing (GE Rail Services) | | | RSRV |
| 1869 | USEX | GENERAL ELECTRIC RAILCAR SERVICES C | | | SCAC4 |
| 1870 | USF | USAfrica Airways, Inc. | Callsign: Africa Express, Ceased operations | USA | AVCODES |
| 1871 | USF | USAfrica Airways | | | ICAO1 |
| 1872 | USFA | UNIQUE SEA FARMS LTD | | | SCAC4 |
| 1873 | USFB | USF BESTWAY, INC | | | SCAC1 |
| 1874 | USFB | USF BESTWAY, INC. | | | SCAC3 |
| 1875 | USFC | U S FUEL INC | | | SCAC4 |
| 1876 | USFD | US FOODSERVICE | | | SCAC4 |
| 1877 | USFG | USF EXPEDITE (DIV OF USF HOLLAND IN | | | SCAC4 |
| 1878 | USFH | UNITED SYSTEMS FREIGHTWAYS LLC | | | SCAC4 |
| 1879 | USFK | USF WORLDWIDE INC. | | | SCAC4 |
| 1880 | USFM | USF GLEN MOORE INC (YRC GL | | | SCAC4 |
| 1881 | USFN | US FREIGHT SOLUTIONS LLC | | | SCAC4 |
| 1882 | USFQ | US FREIGHT LOGISTICS | | | SCAC4 |
| 1883 | USFR | UNITAINER FORWARDER INC | | | SCAC4 |
| 1884 | USFT | U S FREIGHT INC | | | SCAC4 |
| 1885 | USFU | UNITED STATES AIR FORCE | | USA | BIC |
| 1886 | USFU | U.S. DEPT. OF DEFENSE - AIR FORCE | | | PWRC |
| 1887 | USFU | United States Air Force | | | RSRV |
| 1888 | USFU | U S DEPARTMENT OF DEFENSE-AIR FORCE | | | SCAC4 |
| 1889 | USFW | USA FORWARDERS INC | | | SCAC4 |
| 1890 | USFX | U.S. Food Products Car Line Corp. | 7/1923 | | NAKINA |
| 1891 | USFX | Strick Division, Fruehauf Corp. | added 4/1961; 4/1961-7/1965; eliminated 7/1966 | | NAKINA |
| 1892 | USFX | Strick Division, Fruehauf Corp. | added 4/61; 4/61-7/65; eliminated 7/66 | | NRHS |
| 1893 | USFX | *U.S. FOOD PRODUCTS CAR LINE CORP. | | | PWRC |
| 1894 | USFX | *STRICK DIV., FRUEHAUF CORP. | | | PWRC |
| 1895 | USG | UNITED STATES GYPSUM | | | PWRC |
| 1896 | USG | US GOVORA CIECH CHEMICAL GROUP SA | | RO | VKM |
| 1897 | USGC | U S A LOGISTICS INC | | | SCAC4 |
| 1898 | USGG | U S LOGISTICS GROUP LLC | | | SCAC4 |
| 1899 | USGL | US GREENFIBER LLC | | | SCAC4 |
| 1900 | USGS | ULTRASIGN DE MEXICO SA DE CV | | | SCAC4 |
