Idaho State Tax Commission

International Registration Plan (IRP) Vehicles

This guide explains Idaho's sales and use tax laws for IRP registrants. The guide describes motor vehicles, trailers, and glider kits that you can buy tax free under the IRP exemption. It also covers what you must pay tax on, and the requirements for keeping sales and use tax records and for filing returns.

Defining an IRP fleet

A fleet is one or more vehicles registered under the IRP.

  • The fleet must have at least one qualifying motor vehicle. The motor vehicle must have a maximum gross weight of at least 26,000 pounds.
  • The rest of the fleet can consist of a mixture of motor vehicles, trailers and glider-kit vehicles.

An individual or company can have more than one fleet.

Buying exempt for an IRP fleet

You might be able to buy or lease motor vehicles, trailers, and glider-kit vehicles for your IRP fleet tax free if all the following apply:

  • You're a commercial or private carrier in the business of transporting one or more of the following:
    • People
    • Commodities you or someone else owns
  • You'll operate the motor vehicle, glider-kit vehicle or trailer in an IRP fleet substantially used in interstate commerce.
    "Substantially used in interstate commerce" means a fleet that has at least 10 percent of its accrued mileage outside of Idaho in any reporting period. The IRP's reporting period begins July 1 and ends June 30.
  • You complete Form ST-104IC, Sales Tax Exemption Certificate Interstate Commerce Vehicles, and give it to the dealer, retailer or county assessor (or DMV).
Buying motor vehicles exempt
  • The motor vehicle must be at least 26,000 maximum gross weight, and you must immediately register it in an IRP fleet.
  • You can title or base plate the vehicle in any state.
  • You must register a leased vehicle in your business' name.

Farm vehicles or noncommercial vehicles as defined by Idaho Code section 49-123 don't qualify for the exemption.

Buying trailers exempt
  • You must register a rented or leased trailer in your business' name.
  • You must place the trailer in an IRP fleet.
Buying glider kits exempt
  • You must have someone use the glider kit to assemble a glider-kit vehicle*.
  • You must immediately register the glider-kit vehicle in an IRP fleet.

* A "glider-kit vehicle" means every large truck created from a kit that a manufacturer of large trucks makes. The glider-kit vehicle is a new truck chassis, special-ordered from the factory, without engine or transmission. You have someone install a remanufactured engine and transmission into the chassis.

You might qualify for an International Fuel Tax Agreement (IFTA) license if you're an IRP registrant. The license allows you to reduce paperwork and standardize fuels use tax reporting. See IFTA Licensees.

Page last updated April 4, 2019. Last full review of page: April 3, 2019.

This information is for general guidance only. Tax laws are complex and change regularly. We can't cover every circumstance in our guides. This guidance may not apply to your situation. Please contact us with any questions. We work to provide current and accurate information. But some information could have technical inaccuracies or typographical errors. If there's a conflict between current tax law and this information, current tax law will govern.