35 ILCS 505/14a
The Department of Revenue may enter into reciprocal agreements with the appropriate officials of any other state under which the Department may waive all or any part of the requirements imposed by the laws of this State upon those who use or consume motor fuel in Illinois upon which a tax has been paid to such other state, provided that the officials of such other state grant equivalent privileges with respect to motor fuel used in such other state but upon which the tax has been paid to Illinois.
The Department may enter the International Fuel Tax Agreement or other cooperative compacts or agreements with other states or jurisdictions to permit base state or base jurisdiction licensing of persons using motor fuel in this State. Those agreements may provide for the cooperation and assistance among member states in the administration and collection of motor fuel tax, including, but not limited to, exchanges of information, auditing and assessing of interstate carriers and suppliers, and any other activities necessary to further uniformity.
Pursuant to federal mandate, upon membership in the International Fuel Tax Agreement ("Agreement"), the motor fuel use tax imposed upon Commercial Motor Vehicles required to be registered under the terms of the Agreement shall be administered according to the terms of the Agreement, as now and hereafter amended. Illinois shall not establish, maintain, or enforce any law or regulation that has fuel use tax reporting requirements or that provides for the payment of a fuel use tax, unless that law or regulation is in conformity with the Agreement.
The Department shall adopt rules and regulations to implement the provisions of the Agreement.
35 ILCS 505/14a