What Is an MC Number? Explained for Truckers

If you’re entering the world of commercial trucking—especially across state lines—understanding what an MC number is and whether you need one is crucial. While the DOT number identifies a carrier for safety purposes, the MC number establishes the legal authority to transport goods as a for-hire carrier in interstate commerce.

In this guide, we’ll explain what an MC number does, who needs it, how it’s issued, and how it differs from a DOT number. If you’re a trucker or fleet owner, this is information you don’t want to overlook.

 

What Does “MC” Stand For?

“MC” stands for Motor Carrier, and the MC number is a unique identifier issued by the Federal Motor Carrier Safety Administration (FMCSA). It gives trucking companies the authority to operate as a for-hire carrier—specifically when transporting regulated commodities or passengers across state lines.

This number is sometimes called “operating authority,” and it’s what distinguishes private carriers from those hauling freight for others. Without it, even if you have a DOT number, you may not be legally authorized to operate your trucking business.

 

Who Needs an MC Number?

Not every trucking company needs an MC number. The FMCSA only requires it for companies that:

  • Operate as for-hire carriers

  • Engage in interstate commerce

  • Transport regulated commodities or passengers

If you are hauling freight that belongs to other companies and crossing state lines, you fall into this category.

On the other hand, if you’re moving your own goods (as a private carrier), or operating solely within one state with intrastate authority, an MC number might not be necessary. Still, many states have their own rules that may require similar authority even for intrastate operations.

 

How Is an MC Number Different from a DOT Number?

The DOT number and MC number are often confused, but they serve very different purposes.

  • A DOT number is used to track a company’s safety, compliance, and inspection history.

  • An MC number grants legal operating authority for transporting goods or passengers across state lines for pay.

In simple terms: you can have a DOT number without an MC number, but you can’t legally operate as a for-hire interstate carrier without both.

If you’re setting up a trucking company that will cross state lines and haul freight you don’t own, you will likely need both.

 

How to Apply for an MC Number

The application process is handled entirely online through the FMCSA’s Unified Registration System (URS). Most carriers apply for both a DOT and MC number simultaneously if they know they’ll need both.

Step 1: Register Through the URS

Create a new account on the FMCSA website and begin the Unified Registration application. You’ll be asked to provide your business structure, address, contact information, and details about your operations.

Step 2: Select Your Operating Authority

During the process, you’ll be asked to specify the type of operating authority you’re applying for. This includes options like property carrier, passenger carrier, household goods mover, or broker. Select the one that applies to your business model.

Step 3: Pay the Filing Fee

Unlike a DOT number, applying for an MC number requires a non-refundable fee. As of now, the standard cost is $300 per authority. You may need multiple authorities depending on the scope of your services.

 

What Happens After You Apply?

After you’ve submitted your application and payment, the FMCSA assigns your MC number—but it won’t be active right away. There’s a 21-day protest period, during which the public can object to your registration.

In the meantime, you must also submit:

  • Proof of insurance from a licensed insurer

  • A completed BOC-3 form, which designates a process agent in each state

Only once these steps are completed will your authority become active and your MC number usable for operations.

 

Maintaining MC Compliance

Once you receive your MC number, staying compliant is key. That includes:

  • Keeping insurance policies active and up to date

  • Filing biennial updates (every two years) with the FMCSA

  • Operating under the correct authority

  • Responding to safety audits and roadside inspections

Failing to meet these obligations can lead to suspension or revocation of your authority, meaning you’d have to reapply—and possibly lose business in the process.

 

Final Thoughts

An MC number is more than just a registration—it’s your permission slip to legally transport freight or passengers across state lines for compensation. Without it, operating as a for-hire carrier puts you at serious risk of fines, penalties, or shutdown.

Understanding whether you need an MC number—and applying for it correctly—ensures your business gets off to a compliant start. As the backbone of your legal authority, it’s one number that can’t be overlooked.