Private carrier vs for-hire carrier: what's the difference?

The distinction is simple: a private carrier hauls freight owned by the carrier's own company. A for-hire carrier hauls freight that belongs to someone else, for compensation. This distinction determines whether you need operating authority (an MC number) in addition to your USDOT number.

Private carrier

If your trucking operation exists to move your own goods — a manufacturer shipping its own products, a retailer distributing its own inventory — you're a private carrier. You generally need a USDOT number but do not need operating authority to haul your own freight.

For-hire carrier

If you transport goods that belong to others, and you're paid for that transportation, you're a for-hire carrier. You generally need both a USDOT number and operating authority before you can legally operate.

Mixed operations

Some carriers do both — a company that hauls its own products and also takes on paying freight customers. Mixed operations are handled, but the for-hire portion requires operating authority regardless of how small it is relative to the whole operation.