An MC number is a motor carrier operating authority number issued by the Federal Motor Carrier Safety Administration. It grants a company the legal right to transport regulated cargo or arrange transportation for hire across state lines. Every legitimate auto transport company has one, and the record tells you whether that company is a carrier or a broker.
It is free to look up, takes about two minutes, and is the single most useful thing you can do before paying anyone a deposit. MC stands for Motor Carrier, a designation inherited from the old Interstate Commerce Commission. The number appears as "MC-" followed by six or seven digits. The key point most customers miss: an MC number specifies a type of authority. The same registration system issues: A company can hold more than one. Plenty of auto transport businesses carry both carrier and broker authority so they can haul what fits their trucks and broker out the rest.
To get and keep authority, a company must maintain minimum insurance on file with FMCSA — generally $750,000 in liability for property carriers, and a $75,000 surety bond (BMC-84) for brokers — and designate process agents in every state where it operates. Let the insurance lapse and the authority is revoked. How to look one up: go to the FMCSA SAFER system at safer.fmcsa.dot.gov, choose "Company Snapshot," and search by MC number, USDOT number, or company name. Read four fields: Operating Status (must say ACTIVE), Entity Type, Power Units, and Drivers. A real carrier shows a truck count and a driver count. A broker shows zero.
For reference, Baier Transport LLC operates under USDOT 3306263 and MC-1049429. Look us up. The MC record answers the question companies are least eager to answer directly: do you own trucks? A quote from an entity whose authority reads "Broker" means your car will be posted to a load board and hauled by a company you have not evaluated. That may be fine — just know it before you pay, not after.
It also confirms the company is legal. Revoked or inactive authority means no valid insurance filing on record. If something goes wrong with a vehicle moving under revoked authority, your recovery options get complicated fast. And it catches identity games. If the MC number a company gives you comes back registered to a different business name, stop. The biggest mistake is asking for the MC number and never checking it. Companies count on that. The second is confusing MC with USDOT. They are different numbers doing different jobs: USDOT identifies the company for safety monitoring, MC grants the authority to operate for hire interstate. Many carriers have both. Some entities have a USDOT number only, which is a signal worth asking about in interstate auto transport.
Third: an MC number is not an endorsement. It proves licensing and insurance filing, not service quality. Pair the lookup with the safety record, the certificate of insurance, and real reviews. Our red flags guide covers the rest. Baier Transport LLC — USDOT 3306263, MC-1049429, motor carrier authority, our own trucks and our own drivers out of Seabrook, New Hampshire. Check the record, then check the results: 250,000+ vehicles transported and a BBB A+ rating.