| TITandem Industries | Fontana | CA | Computer and Electronic Product Manufacturing334111 | — | ◇ UNVERIFIED |
| TOTec of California | Fontana | CA | Transportation Equipment Manufacturing336992 | — | ◇ UNVERIFIED |
| TOTec of California INC | Fontana | CA | Machinery Manufacturing333924 | — | ◇ UNVERIFIED |
| TCThe Coca Cola Company-fontana | Fontana | CA | Beverage and Tobacco Product Manufacturing312112 | — | ◇ UNVERIFIED |
| TWThe Water Zen LLC | Fontana | CA | Beverage and Tobacco Product Manufacturing312112 | — | ◇ UNVERIFIED |
| TITreasure Islands Manufacturing | Fontana | CA | Electrical Equipment, Appliance & Component Manufacturing335221 | — | ◇ UNVERIFIED |
| TSTreon Steel Fabricators INC | Fontana | CA | Fabricated Metal Product Manufacturing332312 | — | ◇ UNVERIFIED |
| TWTrepco West | Fontana | CA | Beverage and Tobacco Product Manufacturing312230 | — | ◇ UNVERIFIED |
| TPTurret Punch CO INC | Fontana | CA | Chemical Manufacturing325212 | — | ◇ UNVERIFIED |
| TPTurret Punch CO Inc/tpc INC | Fontana | CA | Chemical Manufacturing325211 | — | ◇ UNVERIFIED |
| TPTutor Perini Corporation Equipment Yard | Fontana | CA | Machinery Manufacturing333120 | — | ◇ UNVERIFIED |
| UMUS Mix | Fontana | CA | Nonmetallic Mineral Product Manufacturing327390 | — | ◇ UNVERIFIED |
| UPUS Pipe Fabrication | Fontana | CA | Fabricated Metal Product Manufacturing332996 | — | ◇ UNVERIFIED |
| USU S Reduction CO | Fontana | CA | Primary Metal Manufacturing331492 | — | ◇ UNVERIFIED |
| UCUtility Crane and Equipment INC | Fontana | CA | Transportation Equipment Manufacturing336992 | — | ◇ UNVERIFIED |
| WIWadco Ind INC | Fontana | CA | Fabricated Metal Product Manufacturing332312 | — | ◇ UNVERIFIED |
| WCW C Brown Weldingna INC. | Fontana | CA | Fabricated Metal Product Manufacturing332312 | — | ◇ UNVERIFIED |
| WCWest Coast Liquidators | Fontana | CA | Textile Mills313310 | — | ◇ UNVERIFIED |
| WWWood World Custom Design | Fontana | CA | Wood Product Manufacturing321211 | — | ◇ UNVERIFIED |
| WAWorthington Armstrong Venture | Fontana | CA | Fabricated Metal Product Manufacturing332323 | — | ◇ UNVERIFIED |
| ZMZo Motors North America LLC | Fontana | CA | Transportation Equipment Manufacturing336992 | — | ◇ UNVERIFIED |
