Form ST-108
                                 Sales Tax Affidavit
                                 Untitled Transport Trailer, Office Trailer, and Boat
Buyer’s name                                                        Seller’s name

Buyer’s address                          Phone number               Seller’s address                         Phone number

City                             State   ZIP Code                   City                       State         ZIP Code

                                                      General Information
Use this form when you first register your transport trailer, office trailer, or boat that doesn’t require titling. Idaho imposes 
a use tax on the storage, use, or other consumption of tangible personal property in Idaho on which you didn’t pay sales 
tax, unless an exemption applies. You’ll need to pay use tax or provide proof that you either:
•    Paid sales tax when you bought the property you’re registering, or
•    Completed and provided the appropriate exemption certificate because an exemption applied and no sales tax is 
     due.

                                         Vehicle/Vessel Information
Purchase date                                                       Purchase price

Year                   Make                                   Model                       Identification number: vehicle or vessel

Check the appropriate box.
         Untitled boat                   Untitled office trailer       Untitled transport trailer (utility, horse, semi, etc.)

Homebuilt trailer
If you built the trailer you’re registering and you paid sales or use tax on all the parts, sign and date the statement and 
provide your driver’s license number.

“I certify that I paid tax on all the parts I used to build this trailer. I know that submitting false information can result in 
criminal and civil penalties.”

Name (please print)                                        Driver’s license number                       Date

Signature

Tax collected by a financial institution
A financial institution collecting sales or use tax on a taxable purchase of a transport trailer, office trailer, or boat that isn’t 
titled should complete this section.

“I certify that I collected the required sales tax from the buyer listed at the top of this form. I know that submitting false 
information can result in criminal and civil penalties.”

Financial Institution                                 Idaho seller’s permit number           Financial institution – authorized signature

                      Original – Buyer’s Receipt    | Copy to – County Assessor    | Copy to – Financial Institution
EFO00163     04-15-2020