By Evan Reid, Founder of Haul Handbook · Updated Sep 28, 2026
Idaho is an IFTA member jurisdiction administered by the Idaho State Tax Commission, not by ITD. An Idaho-based carrier qualifies when it travels in Idaho and at least one other IFTA jurisdiction with qualified motor vehicles, applies online through the Taxpayer Access Point (TAP) or on Form IMC-2, and pays $3.00 per decal set. The quarterly return is Form 3150, filed in TAP even when no miles were run, due April 30, July 31, October 31 and January 31. Licenses and decals run January through December, with a two-month display grace period after renewal. Late returns owe the greater of 10 percent of the tax or $50, plus monthly interest.
Idaho IFTA administration
- Agency
- Idaho State Tax Commission (IFTA licenses, decals and returns: (208) 334-7806, or toll-free (800) 972-7660 ext. 7806)
- License fee
- Idaho charges no separate license fee. The IFTA Handbook states that the cost for obtaining an IFTA license is $3.00 per decal set ordered, so the charge is recorded as the decal fee rather than as a license fee.
- Decal fee
- $3 ($3.00 per decal set on the original application, on renewal, and for additional decals ordered during the year. A 30-day temporary decal, for a licensee who needs to put a vehicle in service before decals arrive, costs $10 per unit and is sold at the Tax Commission offices in Boise.)
- Application
- Online application in the Taxpayer Access Point (TAP), or Form IMC-2, Idaho Motor Carrier Application - IFTA only, mailed with payment
- Application: methods
- Complete the application and pay online through TAP (the handbook gives the current TAP address as https://idahotap.gentax.com/TAP/_/ and says TAP moves to tap.tax.idaho.gov beginning November 1, 2026), or mail Form IMC-2 with payment. The Tax Commission mails the license and decals after processing.
- Application: requirements
- An Idaho-based interstate motor carrier that travels in Idaho and at least one other IFTA jurisdiction and operates IFTA-qualified motor vehicles. Only qualified vehicles may join an IFTA fleet, carry the license (cab card) and display decals.
- Filing frequency
- Quarterly, on Form 3150, filed in TAP. The return must be filed even when there was no travel or no tax due; a zero return is submitted without numbers.
- Base jurisdiction: summary
- The base jurisdiction is the jurisdiction where the carrier registers its qualified motor vehicles, maintains operational control and records, and travels some distance in its IFTA fleet vehicles (Articles of Agreement R212 as quoted in the Tax Commission handbook).
- Base jurisdiction: intrastate only
- A carrier with IFTA-qualified vehicles that never or rarely leaves Idaho can register under Idaho's Full Fee (intrastate) registration instead of IRP. A Full Fee carrier that travels into another IFTA jurisdiction may keep Full Fee registration, but then needs an Idaho IFTA license plus either Full Fee registration or temporary registration permits in the other jurisdictions.
- Base jurisdiction: trip permit alternative
- A carrier with IFTA-qualified vehicles registered under IRP in Idaho must either hold an Idaho IFTA license or buy temporary fuels tax permits when traveling in any IFTA jurisdiction, including Idaho.
- Late-filing penalty
- Not filing, filing late, or not paying by the due date draws a penalty of 10 percent of the tax due or $50, whichever is greater, plus interest for each month the return is late by postmark (one day late in a month counts as the whole month). No interest is due for a jurisdiction with no tax due. Partial payments apply first to interest, then tax, then penalty.
More Idaho IFTA rules
- Qualified motor vehicle
- A motor vehicle used, designed or maintained for transportation of persons or property that has two axles and a gross vehicle weight or registered gross vehicle weight over 26,000 pounds, or has three or more axles regardless of weight, or is used in combination when the combination weight exceeds 26,000 pounds. Recreational vehicles are not qualified motor vehicles.
- Credentials: summary
- Every IFTA fleet vehicle must carry a photocopy or accessible electronic copy of the current IFTA license (cab card) and display current decals on the lower rear exterior of each side of the cab. The cab card and decals are issued on first application and again at each annual renewal.
- Credentials: temporary permit
- A 30-day, vehicle-specific IFTA temporary decal is available to a current Idaho licensee who does not have enough decals to put a vehicle in service immediately, at $10 per unit, from the Tax Commission offices in Boise, Monday to Friday, 8 a.m. to 4 p.m.
- License period
- Calendar year. The license and decals are valid January through December and expire December 31.
- Grace period: detail
- After renewing, a licensee has two months to distribute copies of the new license and decals to its fleet vehicles, and must keep displaying the old license and decals during that grace period until the new decals arrive. Renewal decals may go on vehicles before December 31.
- Bond requirement: rule
- A new IFTA licensee does not normally need to post a bond. The Tax Commission may require one for late returns or late tax payments, and may require one when a revoked license is reinstated.
- Renewal
- Licenses expire December 31 and must be renewed, with new decals bought, every year. Current licensees renew online in TAP. A licensee cannot renew until all IFTA returns are filed and all tax, penalty and interest is paid.
- Filing portal: return form
- Form 3150, completed in TAP as a virtual copy of the form. The Tax Commission does not mail paper forms.
- Filing portal: filing steps
- Log in to TAP and select the period to file. Enter fleet miles and gallons for each fuel type so TAP can set fleet miles per gallon, then enter every jurisdiction traveled with total miles, taxable miles and tax-paid gallons purchased. TAP calculates the totals and enters the tax rates, shows an alert when fleet fuel does not equal the total tax-paid volume reported (a double-check, not necessarily an error), and calculates the balance due or credit.
- Filing portal: idaho nontaxable miles
- Idaho does not allow nontaxable miles on the Idaho line of the IFTA return; Idaho nontaxable miles are claimed through the separate fuels tax refund process for IFTA licensees.
- Filing portal: cutoff
- A return submitted in TAP is on time until 11:59 p.m. Mountain Time on the due date. A return can be submitted early with the payment scheduled for the due date.
- Filing portal: zero return
- A return is required even with no travel or no taxable fuel in the quarter; submit it in TAP with no numbers.
- Filing portal: amended returns
- A Form 3150 cannot be amended in TAP. The handbook allows an amendment within three years of filing: download a copy of the original return from TAP (or get a paper copy from the IFTA Help Desk), check the Amended Return box, enter the correct full figures rather than the difference, and on Line 17 enter the amount paid with the original report as a credit in brackets and any refund received as a positive amount.
Quarterly filing deadlines
Returns are due on the same schedule every year. Missing one draws the late-filing penalty above.
Scroll sideways to see every column.
- About these dates
- If the due date falls on a weekend or state holiday, it moves to the next business day. Returns submitted in TAP are timely until 11:59 p.m. Mountain Time on the due date, and a return can be filed early with the payment scheduled for the due date. Amended returns cannot be filed in TAP; the IFTA Help Desk supplies a paper copy.
Licensing rules, records, and penalties
Which vehicles the licence covers, how long it runs, what Idaho can ask you to post or produce, and what a late or wrong return costs. Each one is sourced.
- Qualified motor vehicle
- A motor vehicle used, designed or maintained for transportation of persons or property that has two axles and a gross vehicle weight or registered gross vehicle weight over 26,000 pounds, or has three or more axles regardless of weight, or is used in combination when the combination weight exceeds 26,000 pounds. Recreational vehicles are not qualified motor vehicles.
- Application: Form
- Online application in the Taxpayer Access Point (TAP), or Form IMC-2, Idaho Motor Carrier Application - IFTA only, mailed with payment
- Application: Methods
- Complete the application and pay online through TAP (the handbook gives the current TAP address as https://idahotap.gentax.com/TAP/_/ and says TAP moves to tap.tax.idaho.gov beginning November 1, 2026), or mail Form IMC-2 with payment. The Tax Commission mails the license and decals after processing.
- Application: Requirements
- An Idaho-based interstate motor carrier that travels in Idaho and at least one other IFTA jurisdiction and operates IFTA-qualified motor vehicles. Only qualified vehicles may join an IFTA fleet, carry the license (cab card) and display decals.
- License period
- Calendar year. The license and decals are valid January through December and expire December 31.
- Credentials: Summary
- Every IFTA fleet vehicle must carry a photocopy or accessible electronic copy of the current IFTA license (cab card) and display current decals on the lower rear exterior of each side of the cab. The cab card and decals are issued on first application and again at each annual renewal.
- Credentials: Temporary permit
- A 30-day, vehicle-specific IFTA temporary decal is available to a current Idaho licensee who does not have enough decals to put a vehicle in service immediately, at $10 per unit, from the Tax Commission offices in Boise, Monday to Friday, 8 a.m. to 4 p.m.
- Renewal
- Licenses expire December 31 and must be renewed, with new decals bought, every year. Current licensees renew online in TAP. A licensee cannot renew until all IFTA returns are filed and all tax, penalty and interest is paid.
- Penalties: Revocation
- The Tax Commission may revoke a license for no Idaho IFTA business in the last 12 months, late or partial tax payment, unfiled returns, or failure to follow IFTA rules and recordkeeping requirements, after a mailed notice with 30 days to appeal.
Who needs an Idaho IFTA license
A qualified motor vehicle has two axles and a heavy weight rating, three or more axles, or runs in a heavy combination. An Idaho carrier with such vehicles that runs in Idaho and at least one other IFTA jurisdiction qualifies. A carrier that rarely leaves Idaho can stay on Full Fee registration, and an IRP carrier without a license buys temporary fuel permits instead.
Applying and decals
Apply online through TAP, which the handbook says is moving to a new web address, or mail Form IMC-2 with payment. The Tax Commission mails the license and decals. Each fleet vehicle carries a copy of the license and displays decals on both sides of the cab. A licensee short on decals can buy a vehicle-specific temporary decal in person in Boise.
Quarterly filing and deadlines
Returns are due the last day of the month after each quarter, and a due date on a weekend or state holiday moves to the next business day. TAP accepts returns until late evening Mountain Time on the due date. TAP cannot take an amended return, so the IFTA Help Desk supplies a paper copy for that.
Penalties, records and renewal
Late or missing returns owe a penalty and monthly interest. Keep fuel and mileage records for the retention period the handbook sets. Licenses run on the calendar year, and a licensee cannot renew until every return is filed and paid. After renewal, the grace period lets old decals stay on until the new ones arrive.
The tax rates live in the quarterly matrix
IFTA rates change every quarter, so we keep them in one refreshed store instead of copying them onto every state page. The current quarter is 4Q 2026, effective Oct 1, 2026 through Dec 31, 2026, provisional until Dec 4, 2026. Use the IFTA rates by state table for the full matrix, or the IFTA calculator to run your miles and gallons against the current rates.
For the registration-to-return process in order, follow the Idaho IFTA filing walkthrough.
What pairs with IFTA
IFTA and IRP travel together: the same interstate operation that needs a fuel tax license usually needs apportioned plates through Idaho IRP. If you are still setting up, the full order of operations is in start a trucking company in Idaho.