MC Number
A number issued by FMCSA granting a carrier operating authority to transport regulated cargo or passengers for hire in interstate commerce.
MC numbers (Motor Carrier numbers) are part of FMCSA operating authority and are separate from USDOT numbers. For-hire passenger carriers and many freight-for-hire carriers need an MC number. Carriers that lease owner-operators must hold operating authority. Owner-operators leased to a carrier operate under that carrier's authority, not their own.
Who needs an MC number and who does not
An MC number (operating authority) is required for for-hire carriers transporting regulated commodities in interstate commerce. Private carriers hauling their own goods do not need operating authority — only a USDOT number. Common situations requiring an MC number: for-hire trucking; freight brokerage; for-hire passenger transportation. Owner-operators leased exclusively to one carrier and operating under that carrier's authority generally do not need their own MC number.
MC number vs. USDOT number
These are separate identifiers serving different purposes. A USDOT number identifies a company for FMCSA safety oversight and is required for most CMV operations above threshold weights. An MC number grants the legal right to transport for compensation. A private carrier typically has a USDOT number but no MC number. A for-hire carrier needs both. Operating for hire in interstate commerce without an MC number when one is required is a violation subject to civil penalties and potential out-of-service action.
Last updated: May 28, 2026
When this definition matters
This term usually matters when a driver, owner-operator, or small carrier is deciding whether a federal rule applies, preparing a compliance file, or checking a state CDL step. Use this definition as a starting point, then confirm the controlling requirement in the official source listed below before making a licensing, hiring, dispatch, or recordkeeping decision.
The related terms above are included because they often appear in the same compliance workflow. Reviewing them together can prevent common mix-ups, such as treating a state licensing step as a federal carrier obligation or confusing a driver record with a separate employer record.