What if I'm exempt from sales tax? September 28, 2021 17:54 Updated Proof of tax exemption must be provided at or before picking up your items from the auction location. For auctions held in Minnesota, tax-exempt buyers must provide a Form ST3. Related articles Paying Invoices Online with Mobile Is the item's owner allowed to bid against me? Who do I contact with questions? How Do I Pay My Invoice Online? Filling out the Vehicle Registration Form Comments 0 comments Please sign in to leave a comment.