35 ILCS 105/3-70
The tax imposed by this Act does not apply to the use, in this State, of tangible personal property that is acquired outside this State by a nonresident individual who then brings the property to this State for use here and who has used the property outside this State for at least 3 months before bringing the property to this State.
Where a business that is not operated in Illinois, but is operated in another State, is moved to Illinois or opens an office, plant, or other business facility in Illinois, that business shall not be taxed on its use, in Illinois, of used tangible personal property, other than items of tangible personal property that must be titled or registered with the State of Illinois or whose registration with the United States Government must be filed with the State of Illinois, that the business bought outside Illinois and used outside Illinois in the operation of the business for at least 3 months before moving the used property to Illinois for use in this State.
"Acquired outside this State", whenever used in this Act, in addition to its usual and popular meaning, also means the delivery, outside Illinois, of tangible personal property that is purchased in this State and delivered from a point in this State to a point of delivery outside this State.
35 ILCS 105/3-70