| 901 | ULE | Leisure International Airways Limited. | IATA: MV, | GB | AVCODES |
| 902 | ULG | U Airlines Co. Ltd. | IATA: YL, Founded April 2012. IATA desinator YL recalled. | T | AVCODES |
| 903 | ULG | U Airlines Co. Ltd. | Founded April 2012. IATA desinator YL recalled. | T | AVCODES |
| 904 | ULGI | UNITED LOGISTICS GROUP INC | | | SCAC4 |
| 905 | ULGN | UNITED LOGISTICS GROUP INC | | | SCAC4 |
| 906 | ULGP | UNITED LETTERLOCK GROUP INC | | | SCAC4 |
| 907 | ULGT | UNITED LOGISTICS INC | | | SCAC4 |
| 908 | ULGU | Universal Lng Solution | | | RSRV |
| 909 | ULGW | UNIVERSAL LOGISTICS GROUP WEST INC | | | SCAC4 |
| 910 | ULH | Ultimate Heli (Pty) Ltd | Callsign: Ultimate Heli, | ZA | AVCODES |
| 911 | ULIG | URBAN LOGISTICS INC | | | SCAC4 |
| 912 | ULII | ULTIMATE LOGISTICS INC | | | SCAC4 |
| 913 | ULIO | U & US LOGISTICS INC. | | | SCAC4 |
| 914 | ULIQ | UNI-LINK INC | | | SCAC4 |
| 915 | ULIR | UTI LOGISTIC INC | | | SCAC4 |
| 916 | ULIW | UNLIMITED WAREHOUSING, INC | | | SCAC1 |
| 917 | ULLB | UNLIMITED LOGISTICS LLC | | | SCAC4 |
| 918 | ULLC | UNIMARK LLC | | | SCAC4 |
| 919 | ULLM | ULLMAN OIL INC | | | SCAC4 |
| 920 | ULLQ | US LOGISTICS LLC | | | SCAC4 |
| 921 | ULLV | USCS LOGISTICS LLC | | | SCAC4 |
| 922 | ULM | Stadtwerke Ulm | Real: SWU, City: Ulm | D | TRAFFIC |
| 923 | ULMD | UNLIMITED TRUCKING INC | | | SCAC4 |
| 924 | ULMI | UNILOCK MICHIGAN INC | | | SCAC4 |
| 925 | ULMS | ULTIMATE SEAT COMPANY LTD, THE | | | SCAC4 |
| 926 | ULMU | ULTRAMARINE SERVICE CO | | | SCAC4 |
| 927 | ULNB | ULCH TRAILER SALES LTD | | | SCAC4 |
| 928 | ULOA | UNITRANS INTERNATIONAL INC | | | SCAC4 |
| 929 | ULOC | UNITED LOGISTICS | | | SCAC4 |
| 930 | ULOG | UNIVERSAL LOGISTICS | | | SCAC4 |
| 931 | ULOI | UNION LOGISTICS INC | | | SCAC4 |
| 932 | ULOS | UNLIMITED LOGISTICS | | | SCAC4 |
| 933 | ULOT | UNION LOGISTICS | | | SCAC4 |
| 934 | ULQL | UNIGLOBAL LOGISTICS LLC | | | SCAC4 |
| 935 | ULQW | US COURIER & LOGISTICS - SAN ANTONI | | | SCAC4 |
| 936 | ULR | Ultimate Airways (Pty) Ltd | Callsign: Viper, | ZA | AVCODES |
| 937 | ULRD | UNISHIPPERS | | | SCAC4 |
| 938 | ULRI | ULRICH, RALPH TRUCKING | | | SCAC4 |
| 939 | ULS | Carroll Air Service, Inc. | Callsign: Ulster, | USA | AVCODES |
| 940 | ULS | Ultra Air S.A.S. | IATA: U0, Callsign: Air Ultra, | CO | AVCODES |
| 941 | ULS | Carroll Air Service | | | ICAO1 |
| 942 | ULS | RETIRED 05-15-92 TP (0806) | | | PWRC |
| 943 | ULSE | ULS EXPRESS INC | | | SCAC4 |
| 944 | ULSH | UNLIMITED FREIGHT INC | | | SCAC4 |
| 945 | ULSQ | USA LOGISTICS SERVICES INC | | | SCAC4 |
| 946 | ULSU | UNITED LOGISTIC SERVICES JSC | | | SCAC4 |
| 947 | ULSV | UNIVERSAL LOGISTICS SERVICES INC | | | SCAC4 |
| 948 | ULT | Ultrair, Inc. | Callsign: Ultrair, | USA | AVCODES |
| 949 | ULT | Ultrair | | | ICAO1 |
| 950 | ULT | UppTaget - Upplands Läns Trafik AB | | S | TRAFFIC |
| 951 | ULTC | ULTRACUTS LTD | | | SCAC4 |
| 952 | ULTE | UNLIMITED TRANSPORTATION SERVICES | | | SCAC4 |
| 953 | ULTF | UNILIGHT LTD | | | SCAC4 |
| 954 | ULTG | ULTRAMAR LTD | | | SCAC4 |
| 955 | ULTL | ULTRA LOGISTICS INC | | | SCAC4 |
| 956 | ULTP | ULSTER TRANSPORT INC | | | SCAC4 |
| 957 | ULTS | U-LINE TRANSPORT | | | SCAC4 |
| 958 | ULTT | ULT TRANSPORTATION INC | | | SCAC4 |
| 959 | ULTU | ACE ENGINEERING CO LTD | | ROK | BIC |
| 960 | ULTU | ACE ENGINEERING & CO LTD | | | SCAC4 |
| 961 | ULUI | UNICO LOGISTICS USA INC | | | SCAC4 |
| 962 | ULUN | ULLOA LUNA, CELESTE AIDA | | | SCAC4 |
| 963 | ULXI | ULTRAEX INC | | | SCAC4 |
| 964 | UM | Air Zimbabwe (PVT) Ltd. | ICAO: AZW, Callsign: Air Zimbabwe, IATA Prefix: 168, Name changed from Air Zimbabwe Corporation | ZW | AVCODES |
| 965 | UM | Air Zimbabwe Corporation | ICAO: AZW, Callsign: Air Zimbabwe, IATA Prefix: 168, Name changed to Air Zimbabwe (PVT) Ltd. | ZW | AVCODES |
| 966 | UM | Air Manila, Inc. | ICAO: AMI, Callsign: Airman, Founded in 1964. Merged into Philippine Airlines during 1973. | RP | AVCODES |
| 967 | UMA | Lineas Aereas Del Humaya, S.A. de C.V. | Callsign: Humaya, | MEX | AVCODES |
| 968 | UMA | Lineas Aereas del Humaya | | | ICAO1 |
| 969 | UMAI | U AND M TRUCKING | | | SCAC4 |
| 970 | UMAN | UMA TRANSPORTATION INC | | | SCAC4 |
| 971 | UMAU | UNITED MICROELECTRONICS CORPORATION (SINGAPORE BRANCH) | | SGP | BIC |
| 972 | UMB | Air Umbria, Societa | Callsign: Air Umbria, | I | AVCODES |
| 973 | UMB | Air Umbria | | | ICAO1 |
| 974 | UMBI | UMBRA INC | | | SCAC4 |
| 975 | UMCL | UMC LOGISTICS INC | | | SCAC4 |
| 976 | UMCN | UNIOCEAN MARITIME CO LTD | | | SCAC4 |
| 977 | UMCU | MERCHANT & CHAPMAN | | NL | BIC |
| 978 | UMCU | UZBEK MARITIME CORPORATION | | | SCAC4 |
| 979 | UMDW | UPPER MIDWEST SLEEP LLC | | | SCAC4 |
| 980 | UMEI | ULTIMATE MEDIA EXPRESS INC | | | SCAC4 |
| 981 | UMET | U-MING MARINE TRANSPORT (SINGAPORE) | | | SCAC4 |
| 982 | UMFF | UNITED MAYFLOWER CONTAINER SERVICES | | | SCAC4 |
| 983 | UMFI | UNITED MOTOR FREIGHT INC | | | SCAC4 |
| 984 | UMFO | ULLOA MONTANO, FRANCISCO | | | SCAC4 |
| 985 | UMFT | US MIDWEST FREIGHT INCORPORATED | | | SCAC4 |
| 986 | UMHL | UMMAH LLC | | | SCAC4 |
| 987 | UMIL | ULTIMATE INNOVATIONS LLC | | | SCAC4 |
| 988 | UMIN | UMINA BROS INC | | | SCAC4 |
| 989 | UMJU | AS CONTAINERHANDEL & SERVICE GMBH | | D | BIC |
| 990 | UMK | Aviation Transport Company Yuzmashavia | IATA: 2N, Callsign: Yuzmash, | UA | AVCODES |
| 991 | UMK | Yuzhmashavia | IATA: 2N | | ICAO1 |
| 992 | UMLD | UNICORN MOTORS LTD | | | SCAC4 |
| 993 | UMLS | USMEX LOGISTICS SERVICES LLC | | | SCAC4 |
| 994 | UMLT | UNIMARK LOWBOY TRANSPORTATION INC | | | SCAC4 |
| 995 | UMLU | SMART BULK TERMINAL LIMITED LIABILITY COMPANY | | RUS | BIC |
| 996 | UMMN | UNITED MARINE MANAGEMENT | | | SCAC4 |
| 997 | UMMT | U-MING MARINE TRANSPORT CORPORATION | | | SCAC4 |
| 998 | UMNL | UNITED MARINE NAVIGATION LIMITED, M | | | SCAC4 |
| 999 | UMOL | UHI MARCO OCEAN TRANSPORTATION LIMI | | | SCAC4 |
| 1000 | UMOVE | Umove a/s | | DK | TRAFFIC |
