The MCS-150 biennial update, explained
Every motor carrier must update its MCS-150 with the FMCSA every two years, on a schedule set by the digits of its USDOT number, even if nothing changed and even if the company registered last month. Miss it and the USDOT number can be deactivated. Here is everything you need to know, and nothing you need to pay for.
What the MCS-150 is
The MCS-150, the Motor Carrier Identification Report, is the form behind your USDOT number. It records who you are, where you are, what you haul, how many trucks and drivers you run, and your annual mileage. FMCSA uses it to size your safety scores and to decide when to audit you. The biennial update is the rule that says you must re-file it every 24 months 49 CFR 390.19(b). You must also update within 30 days of any change to your name, address, or operation, but the biennial filing is required regardless.
When yours is due
Look at the last two digits of your USDOT number.
| Last digit | Filing month | Next-to-last digit | Filing year |
|---|---|---|---|
| 1 | January | Odd (1, 3, 5, 7, 9) | Every odd-numbered year |
| 2 | February | ||
| 3 | March | ||
| 4 | April | ||
| 5 | May | ||
| 6 | June | Even (0, 2, 4, 6, 8) | Every even-numbered year |
| 7 | July | ||
| 8 | August | ||
| 9 | September | ||
| 0 | October |
The update is due by the last day of your filing month. Example: USDOT 3456789 ends in 89. Last digit 9 means September; next-to-last digit 8 is even, so even years. Due September 30, 2026, then September 30, 2028.
Skip the math: enter your number in the free calculator.
New carriers: yes, this applies to you
The schedule is tied to the number, not to your registration date. A carrier that registered in December with a number ending in 09 has an update due the following September, nine months later. FMCSA's own guidance is that the initial registration does not reset the cycle. This surprises a lot of first-year carriers, and a first-year deactivation is a bad way to learn it.
How to file, for free, in ten minutes
- Go to fmcsa.dot.gov/registration and choose the update option for existing USDOT numbers. You will need your USDOT PIN. If you never got one or lost it, request it there; it is mailed or emailed, so do this weeks before your deadline, not the day of.
- Confirm or correct your company information, operation type, cargo, number of power units, drivers, and CDL drivers.
- Enter your vehicle miles traveled for the most recent calendar year and the year it covers. This field matters: your safety scores are rated per mile, and a mileage of zero or a stale year skews them against you.
- Certify and submit. Save the confirmation page as a PDF. That is your proof.
What happens if you miss it
- FMCSA deactivates the USDOT number. Brokers and shippers who check your status see "inactive" and stop tendering loads. Roadside, an inactive number is an out-of-service order waiting to happen.
- Civil penalties of up to $1,000 per day, capped at $10,000 per violation 390.19T(b)(4), Appendix B to Part 386.
- Reactivation means filing the overdue update and, if the number was inactive long enough, going through parts of registration again.
Mistakes that cause trouble
- "Nothing changed, so I don't need to file." You do. The biennial update is required even when every field is identical.
- Waiting for a reminder. FMCSA does not reliably send one. Put the month on a calendar that repeats every two years.
- Reporting zero miles. A carrier that runs trucks and reports zero mileage looks like a carrier hiding something. Report the real number.
- Requesting the PIN too late. It does not arrive instantly.
- Letting a filing service change your operation type. Check what was submitted. An error in cargo class or carrier operation can trigger the wrong insurance requirement or an unnecessary audit.
MCS-150 vs UCR: not the same thing
The Unified Carrier Registration is a separate annual fee paid to your base state, due every year for interstate carriers, with fees by fleet size. The MCS-150 is the FMCSA form, due every two years, free. Small carriers routinely pay one and think they have covered the other. You need both.
Keep all of this on one calendar
The DOT Binder tracks driver files, medical cards, annual inspections, maintenance, DVIRs, insurance, UCR, and your MCS-150, and emails you before anything is due. Built for any company with trucks on the road. From $79 a month, 14-day free trial, no card.
Start free trialQuestions
I filed an update six months ago for an address change. Do I still have to file the biennial? If your update was filed within the 12 months before your biennial due date, it generally satisfies that cycle. When in doubt, file again; there is no penalty for updating early or often.
Can I file on paper? Yes, by mail or fax, but processing takes weeks and you lose the immediate confirmation. Online is faster and free.
What if I stopped operating? File the update and mark the operation inactive, or request deactivation. Leaving an abandoned number active invites audits and fees for a company that no longer exists.