(35 ILCS 120/2-51)
    Sec. 2-51. Motor vehicles; trailers; use as rolling stock definition.
    (a) (Blank).
    (b) (Blank).
    (c) This subsection (c) applies to motor vehicles, other than limousines, purchased through June 30, 2017. For motor vehicles, other than limousines, purchased on or after July 1, 2017, subsection (d-5) applies. This subsection (c) applies to limousines purchased before, on, or after July 1, 2017. "Use as rolling stock moving in interstate commerce" in paragraph (13) of Section 2-5 occurs for motor vehicles, as defined in Section 1-146 of the Illinois Vehicle Code, when during a 12-month period the rolling stock has carried persons or property for hire in interstate commerce for greater than 50% of its total trips for that period or for greater than 50% of its total miles for that period. The person claiming the exemption shall make an election at the time of purchase to use either the trips or mileage method. Persons who purchased motor vehicles prior to July 1, 2004 shall make an election to use either the trips or mileage method and document that election in their books and records. If no election is made under this subsection to use the trips or mileage method, the person shall be deemed to have chosen the mileage method.
    For purposes of determining qualifying trips or miles, motor vehicles that carry persons or property for hire, even just between points in Illinois, will be considered used for hire in interstate commerce if the motor vehicle transports persons whose journeys or property whose shipments originate or terminate outside Illinois. The exemption for motor vehicles used as rolling stock moving in interstate commerce may be claimed only for the following vehicles: (i) motor vehicles whose gross vehicle weight rating exceeds 16,000 pounds; and (ii) limousines, as defined in Section 1-139.1 of the Illinois Vehicle Code. Through June 30, 2017, this definition applies to all property purchased for the purpose of being attached to those motor vehicles as a part thereof. On and after July 1, 2017, this definition applies to property purchased for the purpose of being attached to limousines as a part thereof.
    (d) For purchases made through June 30, 2017, "use as rolling stock moving in interstate commerce" in paragraph (13) of Section 2-5 occurs for trailers, as defined in Section 1-209 of the Illinois Vehicle Code, semitrailers as defined in Section 1-187 of the Illinois Vehicle Code, and pole trailers as defined in Section 1-161 of the Illinois Vehicle Code, when during a 12-month period the rolling stock has carried persons or property for hire in interstate commerce for greater than 50% of its total trips for that period or for greater than 50% of its total miles for that period. The person claiming the exemption for a trailer or trailers that will not be dedicated to a motor vehicle or group of motor vehicles shall make an election at the time of purchase to use either the trips or mileage method. Persons who purchased trailers prior to July 1, 2004 that are not dedicated to a motor vehicle or group of motor vehicles shall make an election to use either the trips or mileage method and document that election in their books and records. If no election is made under this subsection to use the trips or mileage method, the person shall be deemed to have chosen the mileage method.
    For purposes of determining qualifying trips or miles, trailers, semitrailers, or pole trailers that carry property for hire, even just between points in Illinois, will be considered used for hire in interstate commerce if the trailers, semitrailers, or pole trailers transport property whose shipments originate or terminate outside Illinois. This definition applies to all property purchased for the purpose of being attached to those trailers, semitrailers, or pole trailers as a part thereof. In lieu of a person providing documentation regarding the qualifying use of each individual trailer, semitrailer, or pole trailer, that person may document such qualifying use by providing documentation of the following:
        (1) If a trailer, semitrailer, or pole trailer is
    
dedicated to a motor vehicle that qualifies as rolling stock moving in interstate commerce under subsection (c) of this Section, then that trailer, semitrailer, or pole trailer qualifies as rolling stock moving in interstate commerce under this subsection.
        (2) If a trailer, semitrailer, or pole trailer is
    
dedicated to a group of motor vehicles that all qualify as rolling stock moving in interstate commerce under subsection (c) of this Section, then that trailer, semitrailer, or pole trailer qualifies as rolling stock moving in interstate commerce under this subsection.
        (3) If one or more trailers, semitrailers, or pole
    
trailers are dedicated to a group of motor vehicles and not all of those motor vehicles in that group qualify as rolling stock moving in interstate commerce under subsection (c) of this Section, then the percentage of those trailers, semitrailers, or pole trailers that qualifies as rolling stock moving in interstate commerce under this subsection is equal to the percentage of those motor vehicles in that group that qualify as rolling stock moving in interstate commerce under subsection (c) of this Section to which those trailers, semitrailers, or pole trailers are dedicated. However, to determine the qualification for the exemption provided under this item (3), the mathematical application of the qualifying percentage to one or more trailers, semitrailers, or pole trailers under this subpart shall not be allowed as to any fraction of a trailer, semitrailer, or pole trailer.
    (d-5) For motor vehicles and trailers purchased on or after July 1, 2017, "use as rolling stock moving in interstate commerce" means that:
        (1) the motor vehicle or trailer is used to transport
    
persons or property for hire;
        (2) for purposes of the exemption under paragraph
    
(13) of Section 2-5, the purchaser who is an owner, lessor, or shipper claiming the exemption certifies that the motor vehicle or trailer will be utilized, from the time of purchase and continuing through the statute of limitations for issuing a notice of tax liability under this Act, by an interstate carrier or carriers for hire who hold, and are required by Federal Motor Carrier Safety Administration regulations to hold, an active USDOT Number with the Carrier Operation listed as "Interstate" and the Operation Classification listed as "authorized for hire", "exempt for hire", or both "authorized for hire" and "exempt for hire"; except that this paragraph (2) does not apply to a motor vehicle or trailer used at an airport to support the operation of an aircraft moving in interstate commerce, as long as (i) in the case of a motor vehicle, the motor vehicle meets paragraphs (1) and (3) of this subsection (d-5) or (ii) in the case of a trailer, the trailer meets paragraph (1) of this subsection (d-5); and
        (3) for motor vehicles, the gross vehicle weight
    
rating exceeds 16,000 pounds.
    The definition of "use as rolling stock moving in interstate commerce" in this subsection (d-5) applies to all property purchased on or after July 1, 2017 for the purpose of being attached to a motor vehicle or trailer as a part thereof, regardless of whether the motor vehicle or trailer was purchased before, on, or after July 1, 2017.
    If an item ceases to meet requirements (1) through (3) under this subsection (d-5), then the tax is imposed on the selling price, allowing for a reasonable depreciation for the period during which the item qualified for the exemption.
    For purposes of this subsection (d-5):
        "Motor vehicle" excludes limousines, but otherwise
    
means that term as defined in Section 1-146 of the Illinois Vehicle Code.
        "Trailer" means (i) "trailer", as defined in Section
    
1-209 of the Illinois Vehicle Code, (ii) "semitrailer", as defined in Section 1-187 of the Illinois Vehicle Code, and (iii) "pole trailer", as defined in Section 1-161 of the Illinois Vehicle Code.
    (e) For aircraft and watercraft purchased on or after January 1, 2014, "use as rolling stock moving in interstate commerce" in paragraph (13) of Section 2-5 occurs when, during a 12-month period, the rolling stock has carried persons or property for hire in interstate commerce for greater than 50% of its total trips for that period or for greater than 50% of its total miles for that period. The person claiming the exemption shall make an election at the time of purchase to use either the trips or mileage method and document that election in their books and records. If no election is made under this subsection to use the trips or mileage method, the person shall be deemed to have chosen the mileage method. For aircraft, flight hours may be used in lieu of recording miles in determining whether the aircraft meets the mileage test in this subsection. For watercraft, nautical miles or trip hours may be used in lieu of recording miles in determining whether the watercraft meets the mileage test in this subsection.
    Notwithstanding any other provision of law to the contrary, property purchased on or after January 1, 2014 for the purpose of being attached to aircraft or watercraft as a part thereof qualifies as rolling stock moving in interstate commerce only if the aircraft or watercraft to which it will be attached qualifies as rolling stock moving in interstate commerce under the test set forth in this subsection (e), regardless of when the aircraft or watercraft was purchased. Persons who purchased aircraft or watercraft prior to January 1, 2014 shall make an election to use either the trips or mileage method and document that election in their books and records for the purpose of determining whether property purchased on or after January 1, 2014 for the purpose of being attached to aircraft or watercraft as a part thereof qualifies as rolling stock moving in interstate commerce under this subsection (e).
    (f) The election to use either the trips or mileage method made under the provisions of subsections (c), (d), or (e) of this Section will remain in effect for the duration of the purchaser's ownership of that item.
(Source: P.A. 100-321, eff. 8-24-17.)