MCS-150 Biennial Update: Who Must File and What Happens If You Don't
Every registered motor carrier is required to periodically confirm and update its information with FMCSA using Form MCS-150 — the Motor Carrier Identification Report. This single form is the source of the Company Census dataset that underlies most of what's publicly known about a carrier's fleet, drivers, and operations, which makes keeping it current more consequential than it might seem for a routine compliance form.
Who has to file
Any company with an active USDOT number is required to file an MCS-150 update on a recurring schedule, regardless of fleet size — a single-truck owner-operator and a large fleet carrier are both subject to the same requirement. It also applies whenever key details change outside the normal cycle, such as a significant change in the number of vehicles or drivers, or a change in the carrier's legal business status.
What the biennial cycle means
"Biennial" means the update is required every two years, on a schedule tied to the last digit of the carrier's USDOT number. FMCSA assigns filing windows so updates are spread across the year rather than everyone filing at once. A carrier is expected to review and resubmit the form even if nothing has changed — confirming the data is still accurate is itself the compliance requirement, not just correcting it when something's different.
What's actually reported on the form
The MCS-150 captures the core facts that make up a carrier's Census record: legal and DBA name, business address, fleet composition (trucks, tractors, trailers, buses), driver counts, the types of cargo hauled, and whether the carrier operates in interstate or intrastate commerce. Every category-page and search feature on this site that references fleet size, driver counts, or cargo type ultimately traces back to this filing. See Data Sources for how it's used here specifically.
Why filing on time matters beyond compliance
An overdue MCS-150 filing is one of the more direct signals that a carrier's registration may not be actively maintained — it doesn't necessarily mean the carrier stopped operating, but it does mean the public record about it is stale. FMCSA can deactivate a USDOT number for failing to file the required update, which can interrupt a carrier's ability to legally operate until it's resolved.
On CarrierPedia, a carrier's most recent MCS-150 filing date is shown on its profile, and a filing older than the two-year requirement is flagged as an outdated filing — a useful signal when evaluating a carrier, since it suggests the underlying registration data (fleet size, driver count, cargo types) may no longer reflect current operations, even if everything else about the carrier looks fine.
Updating outside the regular cycle
Beyond the routine two-year update, FMCSA expects carriers to file a corrected MCS-150 when something material changes sooner than the next scheduled cycle — a significant fleet change, a change in operating status, or a change in business structure. Filing promptly when something changes keeps the public record accurate between the regular biennial updates, rather than leaving a two-year gap where the data doesn't reflect reality.
Checking a filing date
Use DOT Number Lookup to see a specific carrier's most recent MCS-150 filing date as part of its full profile. If you're the one who needs to file or update your own MCS-150, that process runs directly through FMCSA, not through this site — see How to Start a Trucking Company: the FMCSA Registration Path for where registration and ongoing filing requirements fit together.