Motor Fuel Use Tax Rate Change

IL DOR Informational Bulletins

Published January 1st, 2026

Detected March 13th, 2026

Summary

The Illinois Department of Revenue has announced changes to the Motor Fuel Use Tax rates, effective January 1, 2026, through June 30, 2026. These updated rates apply to all International Fuel Tax Agreement (IFTA) licensees operating in Illinois.

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What changed

The Illinois Department of Revenue (IDOR) has issued a bulletin detailing changes to the Motor Fuel Use Tax rates for Part A and Part B, effective from January 1, 2026, through June 30, 2026. The Part A rates for diesel and gasoline will be 55.8¢ and 48.3¢ per gallon, respectively. The Part B rates for diesel and gasoline will be 18.0¢ and 17.0¢ per gallon, respectively. The combined Motor Fuel Use Tax rate for diesel will be 73.8¢ per gallon, and for gasoline, it will be 65.3¢ per gallon during this period.

International Fuel Tax Agreement (IFTA) licensees operating in Illinois must update their systems and reporting to reflect these new tax rates for all fuel purchases and usage occurring from January 1, 2026. Failure to comply with the updated rates could result in penalties or audits by the IDOR. The bulletin also includes a scam alert regarding fraudulent communications impersonating IDOR.

What to do next

Update internal systems and reporting procedures to reflect the new Motor Fuel Use Tax rates effective January 1, 2026.
Ensure all IFTA returns filed for the period of January 1, 2026, through June 30, 2026, accurately use the updated diesel and gasoline tax rates.
Review IDOR's scam alert and reinforce internal controls to prevent falling victim to fraudulent communications.

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Scam Alert: Fake Texts and Websites Impersonating IDOR

Be alert for fraudulent messages or websites attempting to steal your banking information, login credentials, or credit card details. The Illinois Department of Revenue (IDOR) will never request personal or financial information via text message. To confirm official communications or contact details, always visit https://tax.illinois.gov.

Employment Sign Up for Updates

FY 2026-14
December 2025

David Harris, Director

This bulletin is written to inform you of recent changes; it does not replace statutes, rules and regulations, or court decisions.

For more information visit: tax.illinois.gov

Printable version available in:
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FY 2026-14 Change in the Motor Fuel Use Tax Rate, Effective January 1, 2026, through June 30, 2026

To: All International Fuel Tax Agreement (IFTA) Licensees

Illinois Motor Fuel Use Tax is comprised of two parts, Part A and Part B. 35 ILCS 505/13a. This tax is reported and paid by licensees under the International Fuel Tax Agreement (IFTA). The rates listed here are effective January 1, 2026, through June 30, 2026, for use on the quarterly IFTA returns.

What is the Illinois Part A rate?

The Part A rate is the motor fuel tax rate established by Section 2 of the Motor Fuel Tax Law, which imposes the tax per gallon on all motor fuel used in motor vehicles operating on Illinois public highways and in recreational type watercraft operating on Illinois waters. 35 ILCS 505/2.

What are the Illinois Part A motor fuel tax rates from January 1, 2026, through June 30, 2026?

From January 1, 2026, through June 30, 2026, the Part A tax rates (in cents per gallon, DGE 1, or GGE 2) are as follows:

Diesel 3 55.8¢ per gallon

Gasoline 4 48.3¢ per gallon

LPG 55.8¢ per DGE 5

LNG 55.8¢ per DGE 6

CNG 48.3¢ per GGE 7

What is the Illinois Part B rate?

The Illinois Department of Revenue is required to establish the Part B rate of the Motor Fuel Use Tax for diesel fuel, gasoline, gasohol, liquefied petroleum gas (LPG, commonly known as propane), compressed natural gas (CNG), and liquefied natural gas (LNG).

The Part B rate is established by the Department as of January 1 of each year using the average selling price per gallon of motor fuel sold in Illinois during the previous 12 months and multiplying it by 6.25 percent to determine the cents per gallon rate. 35 ILCS 505/13a(2).

What are the Illinois Part B motor fuel tax rates from January 1, 2026, through December 31, 2026?

From January 1, 2026, through December 31, 2026, the Part B tax rates (in cents per gallon, DGE 1, or GGE 2) are as follows:

Diesel 3 18.0¢ per gallon

Gasoline 4 17.0¢ per gallon

LPG 16.2¢ per DGE 5

LNG 14.4¢ per DGE 6

CNG 11.5¢ per GGE 7

What is the Motor Fuel Use Tax rate for January 1, 2026, through June 30, 2026?

From January 1, 2026, through June 30, 2026, the Motor Fuel Use Tax rates for the fuels listed below are as follows: ****

| Fuel | Part A | + | Part B | = | Motor Fuel Use Tax Rate |
| --- | --- | --- | --- | --- | --- |
| Diesel | 55.8¢ | + | 18.0¢ | = | 73.8¢ per gallon |
| Gasoline | 48.3¢ | + | 17.0¢ | = | 65.3¢ per gallon |
| LPG | 55.8¢ | + | 16.2¢ | = | 72.0¢ per DGE |
| LNG | 55.8¢ | + | 14.4¢ | = | 70.2¢ per DGE |
| CNG | 48.3¢ | + | 11.5¢ | = | 59.8¢ per GGE |
Rate information is available at tax.illinois.gov. Use MyTax Illinois at mytax.illinois.gov to renew your IFTA license, order decals, and file and pay quarterly returns.

1 “DGE” means diesel gallon equivalent. 35 ILCS 505/1.8.

2 “GGE” means gasoline gallon equivalent. 35 ILCS 505/1.8.

3 Diesel fuel is defined as any product intended for use or offered for sale as a fuel for engines in which the fuel is injected into the combustion chamber and ignited by pressure without electric spark (includes biodiesel). 35 ILCS 505/2(b); 35 ILCS 105/3-41.

4 Gasoline includes gasohol. See 35 ILCS 105/3-40.

5 A DGE of LPG = 6.41 pounds of LPG. The conversion ratio used to calculate the LPG rate is one gallon = 0.651 DGEs of LPG. 35 ILCS 505/1.8A.

6 A DGE of LNG = 6.06 pounds of LNG. The conversion ratio used to calculate the LNG rate is one gallon = 0.5776 DGEs of LNG. 35 ILCS 505/1.8A.

7 A GGE of CNG = 5.66 pounds of CNG. 35 ILCS 505/1.8B.

Printed by authority of the State of Illinois — Electronic only, One copy