35 ILCS 505/1.2
"Distributor" means a person who either (i) produces, refines, blends, compounds or manufactures motor fuel in this State, or (ii) transports motor fuel into this State, or (iii) exports motor fuel out of this State, or (iv) engages in the distribution of motor fuel primarily by tank car or tank truck, or both, and who operates an Illinois bulk plant where he or she has active bulk storage capacity of not less than 30,000 gallons for gasoline as defined in item (A) of Section 5 of this Law.
"Distributor" does not, however, include a person who receives or transports into this State and sells or uses motor fuel under such circumstances as preclude the collection of the tax herein imposed, by reason of the provisions of the constitution and statutes of the United States. However, a person operating a motor vehicle into the State, may transport motor fuel in the ordinary fuel tank attached to the motor vehicle for the operation of the motor vehicle, without being considered a distributor. Any railroad registered under Section 18c-7201 of the Illinois Vehicle Code may deliver special fuel directly into the fuel supply tank of a locomotive owned, operated, or controlled by any other railroad registered under Section 18c-7201 of the Illinois Vehicle Code without being considered a distributor or supplier.
35 ILCS 505/1.2