| 1501 | UPPT | ULTRA POWER P T CORP | | | SCAC4 |
| 1502 | UPPX | United Producers Pipe Line Co. (Transcontinental Oil Co.) | 7/1930 | | NAKINA |
| 1503 | UPPX | TRANSCONTINENTAL OIL CO. [UNITED PRODUCERS PIPE LINE CO.] | | | PWRC |
| 1504 | UPR | Union Pacific R.R. Co. | 1/1994-7/2005 | | NAKINA |
| 1505 | UPR | Union Pacific R.R. Co. | 1/94-7/2000 | | NRHS |
| 1506 | UPR | UNION PACIFIC RAILROAD COMPANY | | | PWRC |
| 1507 | UPR | Union Pacific Railroad | | | RSRV |
| 1508 | UPR | UNION PACIFIC RAILROAD COMPANY | | | SCAC4 |
| 1509 | UPRI | UNITED PLASTIC RECYCLING INC | | | SCAC4 |
| 1510 | UPRQ | UNION PACIFIC RAILROAD COMPANY | | | PWRC |
| 1511 | UPRQ | Union Pacific Railroad | | | RSRV |
| 1512 | UPRR | UNION PACIFIC RAILROAD COMPANY | | | PWRC |
| 1513 | UPRR | UNION PACIFIC RAILROADS | | | SCAC1 |
| 1514 | UPRR | UNION PACIFIC RAILROAD | | | SCAC4 |
| 1515 | UPRU | UNION PACIFIC RAILROAD COMPANY | | | PWRC |
| 1516 | UPRU | Union Pacific Railroad | | | RSRV |
| 1517 | UPRU | UNION PACIFIC RAILROAD COMPANY | | | SCAC4 |
| 1518 | UPRX | Ultra-Penn Refining Co. | 7/1932-7/1937 | | NAKINA |
| 1519 | UPRX | Pennsylvania-Conley Tank Line, a Division of General American Transportation Corp. | 4/1938 | | NAKINA |
| 1520 | UPRX | Union Pacific Fruit Express Co. | added 1/1978; 1/1980; eliminated 7/1984 | | NAKINA |
| 1521 | UPRX | Ultra-Penn Refining Co. | Apr-38 | | NRHS |
| 1522 | UPRX | Union Pacific Fruit Express Co. | added 1/78; 1/80; eliminated 7/84 | | NRHS |
| 1523 | UPRX | *PENNSYLVANIA-CONLEY TANK LINE, DIV. GENERAL AMERICAN TRANSPORTATION CORP. [ULTRA-PENN REFINING CO.] | | | PWRC |
| 1524 | UPRX | *UNION PACIFIC FRUIT EXPRESS CO. | | | PWRC |
| 1525 | UPRX | Union Pacific Fruit Express | | | RSRV |
| 1526 | UPS | United Parcel Service Company (UPS) | IATA: 5X, Callsign: UPS, IATA Prefix: 406, | USA | AVCODES |
| 1527 | UPS | United Parcel Service | IATA: 5X | | ICAO1 |
| 1528 | UPS | Union Pacific Railroad | | | RSRV |
| 1529 | UPS | United Parcel Services | | | TRAFFIC |
| 1530 | UPSA | UPS AIR FREIGHT SERVICES INC | | | SCAC4 |
| 1531 | UPSB | UPS EXPRESS CRITICAL (AIR) | | | SCAC4 |
| 1532 | UPSC | United Parcel Service | | | SCAC2 |
| 1533 | UPSC | UNITED PARCEL SERVICE OF CANADA LTD | | | SCAC4 |
| 1534 | UPSD | UNITED PARCEL SERVICE SECOND DAY SE | | | SCAC4 |
| 1535 | UPSE | UPS EXPRESS CRITICAL (SURFACE) | | | SCAC4 |
| 1536 | UPSF | UPS FREIGHT SERVICES INC | | | SCAC4 |
| 1537 | UPSG | UPSTAGING INC | | | SCAC4 |
| 1538 | UPSH | UPSHAW, SCOTT TRANSPORTATION | | | PWRC |
| 1539 | UPSH | UPS EXPRESS CRITICAL (CHARTER) | | | SCAC4 |
| 1540 | UPSI | UPS SONIC AIR | | | SCAC4 |
| 1541 | UPSK | UP STATE TRUCKING | | | SCAC4 |
| 1542 | UPSM | UPS MAIL INNOVATIONS INC | | | SCAC4 |
| 1543 | UPSN | United Parcel Service | | | SCAC2 |
| 1544 | UPSN | UNITED PARCEL SERVICE INC | | | SCAC4 |
| 1545 | UPSO | UNITED PARCEL SERVICE COMPANY (CONT | | | SCAC4 |
| 1546 | UPSOM | GHCL UPSOM ROMANIA S.A. | | RO | VKM |
| 1547 | UPSP | UNIPAC SHIPPING INC | | | SCAC4 |
| 1548 | UPSQ | UPS SUPPLY CHAIN SOLUTIONS INC (GOV | | | SCAC4 |
| 1549 | UPSS | UNITED PARCEL SERVICE, INC. (Ohio) | | | SCAC1 |
| 1550 | UPSS | United Parcel Service | | | SCAC2 |
| 1551 | UPSS | UNITED PARCEL SERVICE INC | | | SCAC4 |
| 1552 | UPST | UPSTATE TRUCKING, INC | | | SCAC1 |
| 1553 | UPST | UPSTATE TRUCKING INC | | | SCAC4 |
| 1554 | UPSV | UPS | | | SCAC4 |
| 1555 | UPSW | UPSHAW TRUCKING | | | PWRC |
| 1556 | UPSW | UP SWING AGENCY LTD | | | SCAC4 |
| 1557 | UPSZ | UNITED PARCEL SERVICE | | | PWRC |
| 1558 | UPSZ | United Parcel Service | | | RSRV |
| 1559 | UPSZ | United Parcel Service | | | SCAC2 |
| 1560 | UPSZ | UNITED PARCEL SERVICE | | | SCAC4 |
| 1561 | UPT | Union Pacific Railroad | | | RSRV |
| 1562 | UPTD | UNITED PETROLEUM TRANSPORT LTD | | | SCAC4 |
| 1563 | UPTI | UPS FREIGHT (TL INTERMODAL SERVICES | | | SCAC4 |
| 1564 | UPTL | UPS FREIGHT TRUCKLOAD (DIV OF UPS F | | | SCAC4 |
| 1565 | UPTP | UPRIGHT TRANSPORT | | | SCAC4 |
| 1566 | UPTS | UPS FREIGHT (TL BROKERAGE SERVICES) | | | SCAC4 |
| 1567 | UPTT | UPT UNITED PRODUCT TANKERS HAMBURG | | | SCAC4 |
| 1568 | UPTU | (UPUU) UNION PACIFIC BULKTAINER SERVICE | | | PWRC |
| 1569 | UPTU | Union Pacific Bulktainer Service | | | RSRV |
| 1570 | UPTV | UPSTAGE VIDEO | | | SCAC4 |
| 1571 | UPUU | UNION PACIFIC BULKTAINER SERVICE | | | PWRC |
| 1572 | UPUU | Union Pacific Bulktainer Service | | | RSRV |
| 1573 | UPV | Upavon (Trenchard Lines) | Callsign: Upavon, | GB | AVCODES |
| 1574 | UPWZ | UNITED PARCEL SERVICE | | | PWRC |
| 1575 | UPWZ | United Parcel Service | | | RSRV |
| 1576 | UPWZ | UNITED PARCEL SERVICE | | | SCAC4 |
| 1577 | UPX | Unity Petroleum Corp. | 7/1937-1/1943 | | NAKINA |
| 1578 | UPX | Unity Petroleum Corp. | Apr-38 | | NRHS |
| 1579 | UPX | UNITY PETROLEUM CORP. | | | PWRC |
| 1580 | UPX | Union Pearson Express | | | RSRV |
| 1581 | UPX | Union Pearson Express | City: Toronto, Airport access | CDN | TRAFFIC |
| 1582 | UPY | Union Pacific R.R. | 7/2000-7/2005 | | NAKINA |
| 1583 | UPY | Union Pacific R.R. | Jul-00 | | NRHS |
| 1584 | UPY | UNION PACIFIC RAILROAD | | | PWRC |
| 1585 | UPY | Union Pacific Railroad | | | RSRV |
| 1586 | UPZ | UNION PACIFIC RAILROAD COMPANY | | | PWRC |
| 1587 | UPZ | Union Pacific Railroad | | | RSRV |
| 1588 | UPZ | UNION PACIFIC RAILROAD | | | SCAC4 |
| 1589 | UQ | O'Connor Airlines | ICAO: OCM, Callsign: O'Connor, Name changed from O'Connor-Mt. Gambier's Airline | AUS | AVCODES |
| 1590 | UQ | London European Airways PLC | ICAO: LON, Callsign: European, Name changed to Ryanair Europe. | GB | AVCODES |
| 1591 | UQ | Ryanair Eurpoe | ICAO: LON, Callsign: European, Merged into Ryanair Ireland. Name changed from London European Airways PLC. | GB | AVCODES |
| 1592 | UQ | O'Connor-Mt. Gambier's Airline | ICAO: OCM, Callsign: O'Connor, Name changed to O'Connor Airlines | AUS | AVCODES |
| 1593 | UQ | United African Airlines | | LAR | AVCODES |
| 1594 | UQ | Sky Jet Aviation Ltd. | ICAO: SJA, | EAU | AVCODES |
| 1595 | UQ | Urumqi Airlines Co. Ltd. | ICAO: CUH, Callsign: Loulan, IATA Prefix: 886, | PRC | AVCODES |
| 1596 | UQA | Unique Air FZE | Callsign: Unicargo, | UAE | AVCODES |
| 1597 | UQCS | UNIQUE COURIER SERVICE | | | SCAC4 |
| 1598 | UQEP | UNIQUE EXPRESS INCORPORATED | | | SCAC4 |
| 1599 | UQFI | UNIQUE FREIGHT SYSTEMS INC | | | SCAC4 |
| 1600 | UQUE | UNIQUE TRANSPORTATION INC | | | SCAC4 |
