Glossary · updated October 31, 2026
MX Number
Also known as: MX Authority, Mexican Carrier Authority
By Korey Sharp-Paar · Reviewed by the Fast Trucking Compliance team
Definition
An MX number is the FMCSA operating-authority docket prefix for Mexico-domiciled motor carriers authorized to operate in the United States. MX carriers go through FMCSA vetting and carry the same public-liability insurance and BOC-3 process-agent obligations as U.S. carriers. The MX docket is distinct from the MC docket used by U.S. and Canadian motor carriers and brokers and from the FF docket used by freight forwarders. Like other docket types, it is separate from the USDOT number that identifies the carrier for safety tracking.
Related terms
- Docket Number(MC Docket)
- MC Number(Motor Carrier Number)
- Operating Authority