Washington IFTA Tax Rates for 2026 Q3
Official Washington diesel and gasoline rates for Q3 2026 — and the only state whose IFTA program runs through the Department of Licensing, not a department of revenue.
Washington IFTA Rates for Q3 2026 (Jul - Sep 2026): What Carriers Need to Know
Washington raised its special diesel rate to $0.5950 per gallon on July 1, 2026, up from the $0.5840 that held since July 2025 — the rate change the Department of Licensing posts as a warning banner on its own IFTA pages. Gasoline moved to $0.5650 in the same step. If your quarterly records still carry the old numbers, your tax-paid gallons and your math have drifted apart by more than a cent per gallon.
Washington is the outlier in the IFTA lineup: the Department of Licensing (DOL) administers the program for Washington-based carriers, handling licenses, decals, filings, audits and the License Express online system for prorate and fuel tax accounts. There is no department of revenue between you and your IFTA return in this state — a detail that surprises carriers moving their base state into Washington for the first time.
The DOL mails pre-printed quarterly returns to active accounts, complete with the current IFTA tax rate schedule enclosed. That enclosed sheet is a built-in rate check: compare it against the IFTA Inc. Tax Matrix before signing the quarter. If the numbers disagree on any jurisdiction, the Tax Matrix and the DOL rate-change page are the authoritative sources. Do not use the enclosed schedule as the sole cross-check for states other than Washington.
Washington’s fuel tax rate trajectory matters for budgeting. The table below shows $0.4940 in Q2 2025, $0.5840 from Q3 2025 through Q2 2026, and $0.5950 from Q3 2026. Both increases took effect on July 1 — the start of Washington’s fiscal-year rate cycle — which is why the DOL’s “fuel tax rates changing July 1st” banner appears exactly when carriers are mid-quarter and may not yet have updated their records.
Washington Quarterly Fuel Tax Rates — Last 4 Quarters
1. Filing WA IFTA Returns: Essentials & Deadlines
2. Washington’s Rate Has Been Climbing — Plan Around It
Two increases in two summers: the table above shows $0.4940 in Q2 2025, $0.5840 from Q3 2025, and $0.5950 from Q3 2026. Washington now sits among the five highest diesel rates in the IFTA table.
Both rate changes took effect on July 1 — the start of Washington’s fiscal-year rate cycle — which is why DOL’s “fuel tax rates changing July 1st” banner appears exactly when carriers are mid-quarter. A truck that budgeted $0.4940 per gallon in spring 2025 was undercounting Washington by more than ten cents within fifteen months. For a truck burning 12,000 gallons per quarter in Washington, that 10-cent drift equals $1,200 per quarter in under-accrued tax.
Because the DOL mails the current rate schedule with the pre-printed quarterly return, treat that enclosed sheet as your source check against the Tax Matrix before you sign the quarter. If the numbers disagree, the Tax Matrix and the DOL rate-change page win. For prior quarters, the IFTA Inc. Tax Matrix archive holds the historical rate for each period — use it if you need to amend a prior return.
Washington’s rate volatility means the four-quarter table above is worth reviewing every time you open the return. A rate that moved 1.1 cents between Q2 2026 and Q3 2026 can move again in Q4 2026 or Q1 2027. License Express will reflect the updated schedule automatically, but your own mileage-to-gallon records need to be assigned the correct quarterly rate — not a rate that was accurate three months ago.
WA IFTA Tax Rates — Frequently Asked Questions
The IFTA Inc. Tax Matrix prints $0.5950 per gallon of special diesel for Washington in Q3 2026, effective July 1, 2026. Gasoline is printed at $0.5650 per gallon.
Washington assigns IFTA administration to its Department of Licensing (DOL) rather than a department of revenue — licenses, decals, quarterly returns, audits and the License Express online system all live under DOL. It is the detail that surprises carriers moving their base state to Washington.
Use DOL’s License Express for prorate and fuel tax, or the pre-printed quarterly return DOL mails to active accounts. File every quarter even with no miles — mark “No operation” rather than skipping the quarter to avoid the late-filing penalty.
No. Washington’s $50-or-10% penalty is not due on zero or credit returns — but interest and penalty do apply to returns that owe money and arrive after the due date.
WA ST reports Washington sales use-tax owed on diesel fuel consumed off-road. It is separate from your IFTA tax figure and calculated using the return’s instructions from DOL.
The return instructions single out Oregon, Yukon Territory, Alaska, Northwest Territories and the District of Columbia for individual jurisdiction reporting, alongside the standard per-state IFTA lines.
Washington has adjusted its diesel rate on July 1 in both 2025 and 2026 — the start of the state fiscal year. IFTA rates update quarterly across all jurisdictions, but Washington’s history suggests July is the most active month for rate changes in this state.
No. Washington has no state income tax. The fuel tax — currently $0.5950 per gallon of diesel — is the primary quarterly state-level cost for IFTA carriers based in Washington.
Done looking up rates? Run the numbers.
The rate table tells you what Washington 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