Kentucky KYU Number: Application, Filings, and Audits

A Kentucky KYU number is a weight distance tax license that every motor carrier must have before operating a vehicle with a combined licensed weight above 59,999 pounds on Kentucky’s public highways. It is issued by the Kentucky Transportation Cabinet’s Division of Motor Carriers, and once you hold one, you owe $0.0285 per Kentucky mile driven and must file a return every quarter, even in quarters when you drove no miles in the state.

Who Needs a KYU Number

Under KRS 138.660, the weight distance tax applies to any motor carrier running a vehicle on Kentucky highways with a combined licensed weight over 59,999 pounds.¹ What matters is the licensed weight of the truck, not the load it happens to be carrying. If the vehicle is registered at 60,000 pounds or more, the tax applies whether it’s loaded, empty, or deadheading home.

The rule covers both interstate and intrastate operations. A Tennessee carrier making one delivery to Louisville is treated the same as a Kentucky fleet running the state daily.

Exempt Vehicles

Kentucky’s statutory definition of “motor carrier” leaves out city buses, so local transit is not subject to the tax. Farm vehicles meeting KRS 186.050(4), or an equivalent farm classification in another state, are also excluded.² Farm-plated trucks do not need a KYU number.³

How the Tax Is Calculated

The rate is a flat $0.0285 per mile driven on Kentucky highways.¹ It doesn’t scale with weight above the threshold. A truck licensed at 60,000 pounds pays the same per-mile rate as one at 80,000.

A carrier logging 5,000 Kentucky miles in a quarter owes $142.50. A ten-truck fleet averaging 3,000 Kentucky miles per truck per quarter owes $855 for the quarter. The arithmetic is simple; the record of miles behind it has to be solid.

What You Need Before Applying

Have the following ready before you start:

Your USDOT number, active and current.
Your Federal Employer Identification Number, entered without dashes in the portal.⁴
For each qualifying vehicle, the VIN (capital letters), a unit number, and the highest combined licensed weight it will operate at in Kentucky.⁴
Your legal business name exactly as it appears on your official filings.

An inactive USDOT or a mismatched FEIN will stall the application, so confirm both before you log in.

How to Apply

Apply online through the Kentucky Motor Carrier Portal. You first create a Kentucky Online Gateway account, then enter your business information, USDOT number, FEIN, and vehicle fleet. The KYU number is issued immediately once the application is complete.³

If the online system gives you trouble, you can print the paper application and mail it to the Division of Motor Carriers in Frankfort. Paper processing takes 10 to 14 business days, and nothing is issued until processing finishes.³ Incomplete forms get returned, so a missing field can stretch that window.

Temporary Trip Permits

Carriers who only occasionally cross Kentucky can buy a one-time temporary KYU permit instead of opening a permanent account.³ Each permit covers a single vehicle and must be carried in the cab while in Kentucky. They are purchased through the Motor Carrier Portal. If you find yourself buying them more than a few times, a permanent account is simpler.

Quarterly Filings

Every KYU holder files a weight distance tax return each calendar quarter. Returns are due by the last day of the month after the quarter ends: April 30, July 31, October 31, and January 31.

Starting with the fourth quarter of 2024, all returns must be filed and paid online through the Motor Carrier Portal.³ Paper filing is no longer accepted for returns, though the paper option still exists for the initial application.

Here is the point that catches the most carriers: you must file even when you drove zero Kentucky miles. The return shows zero, but it has to be submitted. Skipping a zero-mile return exposes you to penalties, interest, and a $500 revocation fee on an account that owed no tax to begin with.³ Carriers who stop running Kentucky routes often forget the account exists, miss filings, and run up fees for nothing.

Penalties and Interest

A missed filing can trigger penalty charges, interest, and the $500 revocation fee on the KYU account.³ For the 2026 calendar year, the annual interest rate on unpaid tax is 9%, set each year by the Commissioner of the Department of Revenue under KRS 131.183, with no appeal available on the interest itself.⁵ Interest runs from the original due date, so even a brief delay adds up.

Operating a qualifying vehicle without a valid KYU credential is its own problem. A stop at a weigh station or a roadside inspection without KYU paperwork can mean enforcement action and delays. Getting the account set up before entering Kentucky is cheaper than fixing a violation after the fact.

Recordkeeping and Audits

Keep all mileage records, driver logs, and supporting documentation for five years.⁶ The Kentucky Transportation Cabinet audits KYU accounts, and an audit means producing records that back up every mile on every quarterly return.

Acceptable documentation includes trip reports, fuel receipts, toll records, GPS data, and driver logs. The goal is a clean trail from each vehicle to the reported Kentucky miles. If an auditor finds underreported miles, you owe the additional tax plus interest back to the period in question.

Closing the Account

If you stop operating qualifying vehicles in Kentucky, close the account rather than leave it open. An idle account still needs zero-mile returns, and missed filings generate penalties on a balance of nothing.

To close, file your final quarterly return in the Motor Carrier Portal and select “Ceased Operations” during the filing. If you have no outstanding delinquencies, the Division of Motor Carriers will close the account in good standing and send a confirmation letter. If your last return has already been filed without that checkbox, email tax.dmc@ky.gov with your KYU number to request closure.⁷

After the closure confirmation arrives, carriers with a surety bond on file should ask their surety to send a cancellation notice to the Division. Those with a cash bond may be eligible for a refund by submitting form TC 95-616.⁷

How KYU Differs From IRP and IFTA

The KYU tax is separate from the International Registration Plan and the International Fuel Tax Agreement. IRP covers vehicle registration across states. IFTA covers fuel tax. KYU covers weight-based road usage in Kentucky, with its own registration, its own quarterly return, and its own account.

A truck entering Kentucky without any of these credentials could need three separate trip permits: a Kentucky trip permit for registration, a temporary fuel permit for IFTA, and a temporary KYU permit for the weight distance tax. The mileage you report for KYU often overlaps with IFTA mileage, but each goes on a different form to a different agency. One scope difference matters: IRP and IFTA generally apply above 26,000 pounds, while KYU only applies above 59,999 pounds. Plenty of trucks that need IRP and IFTA will never need a KYU number.

1
Justia Law. Kentucky Revised Statutes 138.660 – Motor Fuels Tax — Surtax — Weight Distance Tax
2
Kentucky Legislative Research Commission. Kentucky Revised Statutes 138.655 – Definitions for KRS 138.660 to 138.7291 and 138.990
3
Kentucky Transportation Cabinet. Kentucky Weight Distance (KYU)
4
Kentucky Transportation Cabinet. KYU Registration Guide
5
Kentucky Department of Revenue. Penalties, Interest and Fees
6
Kentucky Transportation Cabinet. Weight Distance and Intrastate Audit Assistance
7
Kentucky Transportation Cabinet. Going Out of Business