What causes FMCSA to revoke an MC number?

Insurance lapse is the leading cause of involuntary MC revocation. When the BMC-91 cancels and the carrier fails to file replacement coverage, FMCSA initiates the §387 enforcement process: the operating authority is suspended, then revoked if the carrier does not remedy within the §387 timeline. Most insurance-lapse revocations happen within 60 days of the original cancellation effective date if no replacement is filed.

BOC-3 lapse is less common but does happen, typically when a carrier's process-agent provider loses its FMCSA blanket-agent standing (invalidating the BOC-3 on file) and the carrier doesn't notice. The §366.4T obligation to maintain a current designation never goes away; if FMCSA's records show the BOC-3 status as expired or the named provider as unauthorized, FMCSA enforcement follows the §366 procedural path to revocation.

The MCS-150 biennial update is a separate record and a separate penalty. It is due every 24 months on the schedule keyed to your USDOT number (the last digit sets the month, the next-to-last digit sets the odd or even year). A missed update can lead to civil penalties and deactivation of the USDOT number (49 CFR 390.19T(b)(4)). FMCSA has temporarily suspended enforcement and USDOT inactivation for biennial updates due on or after June 1, 2026; the update is still required. What a missed biennial update does not do is revoke your MC authority. File a fresh MCS-150 to reactivate the USDOT number.

UCR non-payment under 49 USC §14504a is often listed alongside these, but it works differently. UCR fees are due annually based on fleet size and the program is administered and enforced by the participating states, not FMCSA: an unregistered carrier faces roadside citations and fines under state law. FMCSA does not revoke MC authority for an overdue UCR filing on its own - revocation is driven by the insurance, BOC-3, out-of-service, penalty, and safety-fitness paths above. Keep UCR current because state enforcement is expensive, not because it threatens the MC number directly.

Safety-driven revocation under §385 is the most severe path - an unsatisfactory fitness rating after a compliance review, repeated OOS violations on PSP, or serious crashes leading to FMCSA out-of-service orders. These are rare for most carriers but always loom for high-volume operators with thin safety margins.