Section 125-318-5 - Purchases subject to exemptionA. Generally.The purchaser of a vehicle, railroad rolling stock, aircraft, or watercraft may claim the 36 M.R.S. §1760(41-A) exemption at the time of purchase or use or pay the sales or use tax due and later request a refund.B.Purchases from a dealer registered to collect Maine sales tax.When the sale of a vehicle, railroad rolling stock, aircraft, or watercraft is claimed to be exempt as an instrumentality of interstate or foreign commerce, the seller must submit, with the sales tax report on which the sale is claimed to be exempt, an affidavit of exemption that has been properly completed and signed by both the seller and the purchaser, on a form prescribed by Maine Revenue Services.C.Purchases at casual sale or outside the State.When a vehicle is purchased at casual sale or from a dealer outside the state, the purchaser must indicate on the vehicle use tax certificate that the property qualifies for exemption as an instrumentality of interstate or foreign commerce. Maine Revenue Services may subsequently require the purchaser to complete and submit an affidavit of exemption. Failure to return a properly completed affidavit of exemption when requested may subject the purchaser to assessment of use tax.D.Affidavit of Exemption.The affidavit of exemption must either indicate a currently valid Interstate Operating Authority number issued by the Federal Motor Carrier Safety Administration to the person shown as the purchaser of the vehicle, or be accompanied by a complete explanation of how the vehicle is used as an instrumentality of interstate or foreign commerce without such authority.E.Payment of tax.If the purchaser who has claimed the exemption finds that the vehicle does not qualify for the exemption because it was not placed in use as an instrumentality of interstate or foreign commerce within 30 days (90 days with good cause) from the date of purchase, or because it was not or will not be used 80% of the days in use as an instrumentality of interstate or foreign commerce during the first two years from the date the property is placed in service, the purchaser is liable for use tax plus all accrued interest. In the case of a vehicle purchased from a dealer registered to collect Maine sales tax, interest accrues from the 15th day of the month that follows the month the vehicle was purchased. In the case of a vehicle purchased outside Maine or at casual sale, interest accrues from the 15th day of the month that follows the month of first use of the vehicle in Maine. The purchaser must report and pay use tax directly to Maine Revenue Services. Payment of the use tax should be accompanied by a letter of explanation. 18- 125 C.M.R. ch. 318, § 5