Home › Guides › How Your MCS-150 Due Date Is Calculated
The FMCSA biennial-update deadline isn't random. It's derived directly from your USDOT number using two of its digits. Once you see the pattern, you can figure out your own due date in about ten seconds.
The MCS-150 is the form you use to update your carrier information with the Federal Motor Carrier Safety Administration (FMCSA). Under 49 CFR 390.19T, most carriers with an active USDOT number must file a biennial update, meaning once every 24 months, even if nothing about the business has changed.
Here is the part that trips people up: FMCSA does not send everyone a bill in January. Your specific due date is baked into your USDOT number itself. Two digits do all the work. The last digit tells you which month, and the second-to-last digit tells you which year. That's the whole rule.
Look at the final digit of your USDOT number. That single number maps to the month your update is due:
Because a single digit only goes from 0 to 9, the schedule only uses ten months. There is no assigned November or December, and the digit 0 lands on October rather than a tenth month past September. Your update is due by the last day of your assigned month.
The month tells you when in the year, but not which year. For that, look at the second-to-last digit of your USDOT number and ask one question: is it odd or even?
If that digit is odd, you file in odd-numbered years (2025, 2027, 2029, and so on). If it is even (including 0, which counts as even), you file in even-numbered years (2026, 2028, 2030). Combine the two rules and you have a fixed month-and-year slot that repeats every 24 months for as long as your number is active.
Take a made-up USDOT number: 1234567.
Step one, the last digit is 7, which maps to July. Step two, the second-to-last digit is 6, which is even, so this carrier files in even-numbered years. Put together, this carrier's MCS-150 biennial update is due by the end of July in every even year: July 31, 2026, then July 31, 2028, and so on.
Try it with your own number. Read the last digit for the month, check whether the second-to-last digit is odd or even for the year, and you have your recurring deadline. If you would rather not do it by hand, our free MCS-150 due-date calculator does the same two steps for you and shows your next date.
A few things surprise carriers the first time. First, the update is required even if nothing changed. No new trucks, no new address, no new mileage bracket still means you file, because the biennial update also confirms your operation is still active. Skipping it can lead FMCSA to deactivate your USDOT number.
Second, certain changes require you to file sooner than your biennial slot, such as a change of address, company name, or going out of business. Your two-digit schedule sets the routine deadline; a material change can move it up. Third, if your assigned month has already passed this year and it's your year to file, you may already be overdue, so it's worth checking today rather than waiting.
The USDOT digit trick only governs the MCS-150. Your other recurring obligations run on their own calendars, and mixing them up is a common way to get caught off guard.
The IRS Form 2290 Heavy Highway Vehicle Use Tax runs on a tax period from July 1 through June 30; for a vehicle used in July, the return is generally due by the end of August, with different timing for vehicles first used later in the period. Confirm current amounts and dates with the IRS. Unified Carrier Registration (UCR) is an annual renewal whose fees are set year to year, so check the official UCR portal rather than relying on last year's number. If you run interstate, IFTA fuel-tax returns are quarterly and IRP apportioned plates renew annually through your base state. Where a figure changes each year, we deliberately don't print it here; go to the official agency for the live number.
The MCS-150 math is simple, but remembering a date that only comes around every two years is the hard part, especially when 2290, UCR, IFTA, and IRP each have their own clock. That's the gap DOTDeadline is built to close: the free calculator shows your MCS-150 date now, and the paid reminder service nudges you before each filing so nothing lapses quietly.
One honest note: this article is general information, not legal or tax advice, and DOTDeadline is not affiliated with or endorsed by FMCSA or the IRS. Your exact due date and any recent rule changes should always be confirmed directly with the official agency before you file.
Your MCS-150 biennial-update deadline is encoded in your USDOT number: the last digit sets the month (1=Jan through 9=Sep, 0=Oct) and the second-to-last digit sets the year (odd digit = odd years, even = even years), repeating every 24 months. Read those two digits, or use the free calculator, and confirm with FMCSA before filing.
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.