Illinois IFTA Tax Rates for 2026 Q3
Official Illinois Motor Fuel Use Tax (MFUT) rates for Q3 2026 — plus the USDOT-first registration rule, MyTax Illinois filing, and the renewal deadline that suspends late filers.
Illinois IFTA Rates for Q3 2026 (Jul - Sep 2026): What Carriers Need to Know
Illinois prints $0.7380 per gallon of special diesel and $0.6530 per gallon of gasoline for Q3 2026 — among the highest per-gallon rates in the current IFTA table, though a touch lower than the $0.7490 diesel rate Illinois charged through Q4 2025. Every gallon you burn in Illinois is felt in the quarterly total, which is why this state earns its own line on any handwritten rate sheet carried in a cab.
Illinois runs IFTA under a different name: the Motor Fuel Use Tax (MFUT), administered by the Illinois Department of Revenue (IDOR). For IFTA purposes the tax works identically — you still file quarterly, report miles and gallons by jurisdiction, and settle the net owed or refunded — but Illinois statutes and IDOR publications reference the MFUT label. Carriers sometimes miss IDOR communications because they are scanning for “IFTA” and the heading says “MFUT.”
Illinois has a registration prerequisite that most other IFTA states skip: you need a USDOT number from the U.S. Department of Transportation before you can register for MFUT with IDOR. If your operation is new and you have not yet applied for a USDOT number, that application must come first. The USDOT number is issued by the Federal Motor Carrier Safety Administration (FMCSA) and is separate from your IRP apportioned plate credentials.
IDOR registration for the Motor Fuel Use Tax is handled through MyTax Illinois (the online account portal) or by submitting Form MFUT-12 (Motor Fuel Use Tax IFTA License and Decals Application). The IFTA license itself carries no fee, but decals are priced separately and must be ordered as part of the application. Each set of decals covers one qualified motor vehicle for one calendar year, and carriers must order new decals annually.
Illinois Quarterly Fuel Tax Rates — Last 4 Quarters
1. Filing IL IFTA Returns: Essentials & Deadlines
2. Does Illinois MFUT Even Apply to You?
Two Illinois specifics catch carriers out: the qualified-vehicle weight threshold and the Single Trip Permit alternative for occasional operations.
Illinois draws the MFUT line at qualified motor vehicles — combinations over 26,000 pounds (11,793 kilograms) combined gross vehicle weight fall inside the regime. This mirrors the standard IFTA qualified-motor-vehicle definition, so most interstate tractor-trailer combinations are in scope. Carriers making only occasional trips into or out of Illinois can obtain a Single Trip Permit (STP) instead of licensing. The STP covers 96 hours of operation and is sold through most wire services for an additional fee per vehicle.
For any operation running Illinois lanes regularly, the per-trip STP cost accumulates quickly. A license and decals amortize across the full year and all trips, making them the economical choice for carriers with more than a handful of annual Illinois crossings. The math: if the STP fee per vehicle per trip is $20 and you make six Illinois trips annually, the STP route costs $120 per year per truck before any fuel tax consideration — compare that against a one-time decal fee and you will generally prefer the license.
The only qualified motor vehicles exempt from MFUT registration in Illinois are the narrow statutory exceptions IDOR lists on its licensing page — government vehicles, farm vehicles operating within a certain radius, and a few others. Assume your tractor-trailer combination is in scope until you have confirmed with IDOR that a specific exemption applies. Operating in Illinois without either a valid MFUT license or an STP is a compliance violation that can result in fines at a weigh station.
IL IFTA Tax Rates — Frequently Asked Questions
The IFTA Inc. Tax Matrix prints $0.7380 per gallon of special diesel for Illinois in Q3 2026, with gasoline at $0.6530. Illinois dropped from $0.7490 diesel starting Q1 2026.
Illinois administers IFTA under state law as the Motor Fuel Use Tax (MFUT), managed by IDOR. Same quarterly rhythm, same jurisdiction reporting, same IFTA agreement — the name on Illinois forms and publications is MFUT, not IFTA.
A USDOT number from the Federal Motor Carrier Safety Administration. IDOR will not process an Illinois MFUT registration without one. After the USDOT number is in hand, register through MyTax Illinois or file Form MFUT-12.
There is no fee for the IFTA license itself. Decals are priced separately and required per qualified motor vehicle per year. The total cost depends on your fleet size — the MFUT-12 application or your MyTax Illinois account shows the current decal schedule.
Renew electronically by December 31 and you keep a grace period while new decals are in transit. After January 1 there is no grace period — IDOR flags the license as suspended, which is an operating violation under IFTA.
For occasional runs, yes: the Single Trip Permit covers 96 hours and is available through most wire services. For more than a few Illinois trips per year, the per-trip fee quickly exceeds the cost of a license and decals.
Combinations over 26,000 pounds (11,793 kilograms) combined gross vehicle weight are qualified motor vehicles subject to MFUT. This is the standard IFTA threshold — most OTR tractor-trailer combinations are well above it.
No separate surcharge is flagged for Illinois in the IFTA Tax Matrix. The $0.7380 per-gallon diesel rate is the complete figure for Q3 2026.
Done looking up rates? Run the numbers.
The rate table tells you what Illinois charges per gallon. The calculator turns that into your actual quarterly return, and the mileage tracker splits your miles state by state.
Browse the full 48-state rates table