Idaho IFTA Fuel Tax Rate, 3rd Quarter 2026
Idaho's IFTA diesel rate for the 3rd quarter of 2026 is $0.3200 per gallon, unchanged from Q2 2026.
Idaho rate for Q3 2026
Special diesel, Q3 2026
$0.3200
per US gallon, unchanged from Q2 2026
- Diesel tax rate
- $0.3200/gal
- Surcharge
- None listed
- Quarter
- Q3 2026, from Jul 1, 2026
- Change vs last quarter
- unchanged
Notes from the source
Matrix footnote #6 (IDAHO): FUEL PURCHASED ON IDAHO INDIAN RESERVATIONS - As of November 1, 2007, diesel purchased from retail outlets on the Shoshone- Bannock Indian Reservation is Idaho tax-paid diesel for IFTA reporting & refund. Diesel purchased from Coeur D\'Alene & Nez Perce tribe outlets is not Idaho tax-paid diesel for IFTA reporting and refund purposes. Questions, please call toll free 800-972-7855 ext 7855.
Worked example: the Idaho line of your IFTA return
Change the numbers to match your quarter. Prefilled with 10,000 total miles on 1,550 gallons, 1,200 of those miles in Idaho, and 100 gallons bought there.
Idaho vs. its neighbors, Q3 2026
| Jurisdiction | Diesel + surcharge | vs. ID |
|---|---|---|
| Washington | $0.5950 | +$0.2750 |
| British Columbia | $0.4060 | +$0.0860 |
| Utah | $0.3790 | +$0.0590 |
| Idaho | $0.3200 | — |
| Montana | $0.2975 | −$0.0225 |
| Nevada | $0.2700 | −$0.0500 |
| Wyoming | $0.2400 | −$0.0800 |
| Oregon | $0.0000 | −$0.3200 |
On an IFTA return, a higher rate doesn't mean you pay more overall. Fuel you buy in a high-rate state earns a bigger credit. What matters is where you burn the fuel versus where you buy it.
Idaho rate, last 4 quarters
Source: IFTA, Inc. Fuel Tax Rate Matrix, 3rd Quarter 2026 · Effective Jul 1, 2026 · Last verified Sep 28, 2026
IFTA, Inc. publishes the rates each member jurisdiction reports. Idaho's tax agency is the final word on its rate.
Estimates for planning. Confirm with your tax pro or your base jurisdiction's IFTA office before filing.