Home › Guides › What Is the MCS-150 Biennial Update (and Why It Matters)
If you run under a USDOT number, the government expects you to refresh your details every two years, even when nothing has changed. Here is what the MCS-150 is, when yours is due, and why missing it can quietly shut down your authority.
The MCS-150 is the form you use to register your operation with the Federal Motor Carrier Safety Administration (FMCSA) and to keep that registration current. It is officially called the Motor Carrier Identification Report, and it is what creates and maintains your USDOT number.
The information on it is basic but important: your legal and DBA name, principal address, the number of trucks you run (power units), the number of drivers, the type of operation, and your mileage for the most recent year. FMCSA and roadside inspectors use this profile to understand who you are and how safety rules apply to you.
This is general information for owner-operators and small fleets, not legal advice. DOTDeadline is an independent service and is not affiliated with or endorsed by FMCSA or the IRS. When something specific to your operation is on the line, confirm it with the agency directly.
The part that trips people up is that the MCS-150 is not a one-and-done filing. Under 49 CFR 390.19T, most carriers must update their MCS-150 every 24 months, on a recurring schedule. This is the biennial update.
The most common misconception is that you only have to file when something changes. That is not how the rule works. Even if your address, truck count, and mileage are identical to two years ago, you are still required to submit the update to confirm your information is accurate. Filing nothing is not the same as filing an unchanged report.
You also update outside the two-year cycle whenever key facts change, but the biennial deadline stands on its own regardless.
Your deadline is not the anniversary of when you registered. It is baked into your USDOT number itself, using two digits.
The month comes from the last digit of your USDOT number: 1 means January, 2 February, and so on through 9 for September, with 0 meaning October. So a number ending in 5 is due in May; a number ending in 0 is due in October.
The year comes from the second-to-last (next-to-last) digit. If that digit is odd, you file in odd-numbered years; if it is even, you file in even-numbered years. For example, USDOT 123456 ends in 6 (June) with a next-to-last digit of 5 (odd), so its update is due in June of every odd year.
If the arithmetic feels fiddly, that is exactly what our free MCS-150 due-date calculator on this site is for: enter your USDOT number and it shows your month and year, no sign-up required.
Missing the biennial update is not a harmless oversight. The regulation is explicit that failure to complete the update can lead to deactivation of your USDOT number and to civil penalties.
A deactivated USDOT number is the serious one. It can effectively stop you from operating legally, and brokers, shippers, and insurers who check your status may see you as not in good standing. Getting reactivated means scrambling to file while your trucks sit.
Civil penalties for failing to file, or for filing misleading information, are set by federal statute and are adjusted for inflation every year, so the exact dollar figures move over time. Because of that, we will not quote a number that could be out of date; check the current amounts on FMCSA's official site rather than trusting any fixed figure you read secondhand.
Here is the good news that a lot of third-party sites do not advertise: filing your MCS-150 biennial update directly with FMCSA is free. You submit it online through FMCSA's official portal at fmcsa.dot.gov.
You will run into companies that charge a fee to file it for you, sometimes framing it as urgent or mandatory-through-them. It is not. Paying a service is a convenience choice, never a requirement, and the government charges nothing for the update itself.
Keep your registration login details somewhere safe, because you will need them each cycle. The filing is quick once your numbers are in front of you.
The MCS-150 is only one item on a carrier's compliance calendar, and it is easy to mix them up. A few that are separate and run on their own schedules:
UCR (Unified Carrier Registration) is a separate annual fee-based registration, not the same as the free MCS-150.
Form 2290 Heavy Vehicle Use Tax (HVUT) is an IRS filing for heavier trucks, with its own annual deadline and its own portal at irs.gov.
IFTA fuel tax and IRP apportioned plates are administered through your base state and have their own quarterly or annual timelines.
Each of these has a different agency, a different due date, and a different consequence for slipping. That fragmentation is exactly why a single reminder in advance of each one is worth having, so none of them catches you off guard.
Your MCS-150 biennial update is required every 24 months even if nothing changed, its due date is encoded in your USDOT number (last digit = month, next-to-last digit = odd/even year), missing it risks USDOT deactivation and civil penalties, and it is free to file directly with FMCSA. Check your date with the free calculator on this site and confirm specifics with the agency.
Enter your USDOT number once and see your MCS-150 due date free — then keep every federal deadline in one place.
Check my date →DOTDeadline is an independent reminder tool. It is NOT affiliated with, endorsed by, or connected to the FMCSA, the U.S. DOT, the IRS, or any government agency. General information only — not legal, tax, or compliance advice. Always confirm with the official agency.