What Is an MC or MX Number and Who Needs One?

An MC or MX number is federal operating authority issued by the Federal Motor Carrier Safety Administration (FMCSA) that lets a business haul freight or passengers, or arrange transportation, for pay across state lines. You need one before you accept your first load or fare. Which number applies depends on where your company is based and what it does: MC numbers go to U.S.-based for-hire carriers and freight brokers, and MX numbers go to Mexico-domiciled carriers entering the United States.¹²

MC, MX, and FF: What Each One Covers

The MC (Motor Carrier) number is the most common form of operating authority. It covers trucking companies hauling federally regulated commodities for hire, household goods movers, bus and shuttle operators carrying passengers across state lines, and freight brokers who arrange loads without taking possession of the cargo.¹

The MX number does the same work for Mexico-domiciled motor carriers. Any Mexican carrier bringing freight into the United States must hold one, whether it stays inside a border commercial zone or runs deeper into the country.²

The FF (Freight Forwarder) number is separate. It goes to companies that arrange shipments and assume liability for the cargo without owning the trucks. That liability piece is what distinguishes a forwarder from a broker: a broker connects a shipper with a carrier and never takes possession of the goods, while a forwarder takes responsibility for them.¹

How Operating Authority Differs From a USDOT Number

Almost every commercial vehicle operator in interstate commerce needs a USDOT number for safety tracking. That is a separate requirement from operating authority. The USDOT number identifies you for safety purposes; the MC, MX, or FF number is what allows you to run the business for pay.³ A company that runs both a trucking operation and a brokerage may need more than one operating authority.

Who Needs an MC or MX Number

You need operating authority if your business does any of the following in interstate commerce for compensation:

Hauls property that belongs to someone else, including truckload, less-than-truckload, and household goods.
Carries passengers, whether by bus, shuttle, or charter.
Arranges transportation as a freight broker.

Freight forwarders fall under the FF category, and Mexico-based carriers fall under MX.⁴

Who Doesn’t

Several kinds of operations are outside the requirement:

Private carriers hauling their own goods in their own trucks. A manufacturer moving its own products between its own facilities needs only a USDOT number.
For-hire carriers that exclusively transport commodities not federally regulated, such as certain agricultural products.
Carriers operating entirely within a federally designated commercial zone, which can span parts of several states around a major metro area.
Carriers that run only within a single state. Federal operating authority does not apply to purely intrastate business, though the state itself may impose its own registration rules.⁴

What It Takes to Get One

New applicants register through the FMCSA’s Unified Registration System (URS) online. The system issues both a USDOT number and the appropriate MC, MX, or FF number in the same process. You provide your company name, address, type of operation, and the cargo or passengers you plan to carry.⁵

The filing fee is $300 for each type of operating authority you request, and it is non-refundable. Two different types of authority means $600; two authorities within the same category, such as common and contract carrier authority for property, means one $300 fee.⁶

Insurance

The FMCSA will not activate your authority until the required financial responsibility is on file. Amounts vary by operation. General freight carriers running vehicles at 10,001 pounds GVWR or more must carry $750,000 in bodily injury and property damage liability. Hazardous materials carriers face higher minimums, up to $5,000,000 for explosives, poison gas, or radioactive materials. Passenger carriers with vehicles seating 16 or more people need $5,000,000 as well. Household goods movers carry $750,000 in liability plus $5,000 in cargo coverage.⁷

Brokers and freight forwarders do not carry liability insurance in the same way. They must maintain a $75,000 surety bond or trust fund, filed with the FMCSA on Form BMC-84 or BMC-85, that protects shippers and carriers if the broker fails to honor its contracts.⁸

BOC-3 Process Agent

Every applicant must file a BOC-3 form designating a process agent in each state where the company operates. A process agent is a person or company authorized to accept legal documents for you. For carriers with commercial vehicles, only the process agent can file the form; brokers and freight forwarders without trucks can file it themselves.⁹

The Protest Period

Your authority does not activate the day you submit the application. The FMCSA publishes the filing for a protest period during which competitors or the public can object. Only after that window closes, and after the agency confirms your insurance and BOC-3, does the authority become active. Plan on several weeks between submitting and hauling.⁷

What Operating Without Authority Costs

Running a for-hire operation without proper operating authority is expensive. Property carriers face a minimum penalty of $13,676 per violation. Passenger carriers face a minimum of $34,116. Household goods transporters operating without registration face a minimum of $39,615. Foreign carriers running outside commercial zones without authority can be fined up to $18,766 for an intentional violation, and up to $46,918 for a pattern of intentional violations. Each load, each trip, and each day of continued operation can be counted as a separate offense.¹⁰

Keeping Your Authority Active

Approval is not the end of the compliance work. New carriers enter an 18-month monitoring period, and within the first 12 months of beginning operations an FMCSA-certified investigator or state officer will conduct a safety audit at your principal place of business. The audit reviews safety management practices, vehicle maintenance records, and driver qualifications. Failing without correcting the deficiencies leads to revocation of your USDOT registration.¹¹

Motor carriers must also update their registration information every 24 months by filing an MCS-150 form, with the filing month set by the last digit of the USDOT number. Any change in address, phone number, or fleet size must be reported within 30 days.¹²

Your authority stays active only as long as your insurance stays on file. If an insurer cancels a policy and no replacement is filed, the FMCSA revokes the authority. The same applies to a lapsed surety bond for a broker or freight forwarder.⁷

Reinstatement

If your authority is revoked because of an insurance lapse or a missing BOC-3, you can apply for reinstatement rather than restart the whole registration. It costs $80 and is typically processed within a week. You need an active USDOT number with current contact information, current minimum insurance, and a valid BOC-3 on file. Reinstatement is not available if the authority was revoked under an imminent hazard order or a final unsatisfactory safety rating.¹³

Checking Another Carrier’s Authority

Shippers, brokers, and anyone hiring a carrier can verify operating authority for free through the FMCSA’s SAFER (Safety and Fitness Electronic Records) system. The Company Snapshot tool takes a USDOT number, an MC or MX number, or a company name and returns the carrier’s identification, safety record, insurance status, and out-of-service history.¹⁴ Running that check before tendering a load is one of the simplest ways to keep yourself off the hook for hiring an unauthorized carrier.

1
Federal Motor Carrier Safety Administration. What is Operating Authority (MC number) and who needs it?
2
Federal Motor Carrier Safety Administration. Cross-Border Operating Requirements for Mexico-domiciled Motor Carriers
3
Federal Motor Carrier Safety Administration. Getting Started with Registration
4
Federal Motor Carrier Safety Administration. Get Operating Authority
5
Federal Motor Carrier Safety Administration. How Do I Register for a USDOT Number
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Federal Motor Carrier Safety Administration. What is the cost for obtaining operating authority (MC/FF/MX number)?
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Federal Motor Carrier Safety Administration. Insurance Filing Requirements
8
eCFR. 49 CFR Part 387 Subpart C – Surety Bonds and Policies of Insurance for Motor Carriers and Property Brokers
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Federal Motor Carrier Safety Administration. Form BOC-3 – Designation of Agents for Service of Process
10
Law.Cornell.Edu. 49 CFR Appendix B to Part 386 – Penalty Schedule
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Federal Motor Carrier Safety Administration. New Entrant Safety Assurance Program
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Federal Motor Carrier Safety Administration. When am I required to file a biennial update?
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Federal Motor Carrier Safety Administration. Frequently Asked Questions
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Federal Motor Carrier Safety Administration. Company Snapshot