Illinois Statutes Chapter 35. Revenue § 636/5-10. Authority

(a) The act or privilege of originating in such municipality or receiving in such municipality intrastate telecommunications by a person. To prevent actual multi-municipal taxation of the act or privilege that is subject to taxation under this subsection, any taxpayer, upon proof that the taxpayer has paid a tax in another municipality on that event, shall be allowed a credit against any tax enacted pursuant to or authorized by this Section to the extent of the amount of the tax properly due and paid in the municipality that was not previously allowed as a credit against any other municipal tax. However, such tax is not imposed on such act or privilege to the extent such act or privilege may not, under the Constitution and statutes of the United States, be made the subject of taxation by municipalities in this State.

(b) The act or privilege of originating in such municipality or receiving in such municipality interstate telecommunications by a person. To prevent actual multi-state or multi-municipal taxation of the act or privilege that is subject to taxation under this subsection, any taxpayer, upon proof that the taxpayer has paid a tax in another state or municipality in this State on such event, shall be allowed a credit against any tax enacted pursuant to or authorized by this Section to the extent of the amount of such tax properly due and paid in such other state or such tax properly due and paid in a municipality in this State which was not previously allowed as a credit against any other state or local tax in this State. However, such tax is not imposed on the act or privilege to the extent such act or privilege may not, under the Constitution and statutes of the United States, be made the subject of taxation by municipalities in this State.