Amends the Local Government Taxpayers' Bill of Rights Act. Provides that the statute of limitations set by a unit of local government for the determination and assessment of taxes covered by the Act may not exceed 10 years (currently, 4 years) after the end of the calendar year for which the return for the period was filed or the end of the calendar year in which the return for the period was due, whichever occurs later. Makes conforming changes concerning the tolling of this 10-year period. Amends the Illinois Municipal Code. In a Section concerning municipal audits of public utilities, provides that municipalities may request information from public utilities no more than annually (currently, no more than once every 2 years). Provides that, if the public utility fails to respond in a timely manner to the request for information with complete information, the public utility shall be liable to the municipality for a penalty of $1,000 for each day it fails to produce the requested information. Provides that, if a public utility is liable for any error in past tax payments in excess of $5,000 that were unknown prior to an audit from the municipality, then the public utility shall reimburse the municipality for the cost of the audit. Sets forth conditions under which the public utility may be liable for attorney's fees incurred by the municipality. Senate Floor Amendment No. 1 Adds reference to: 220 ILCS 5/9-224.1 new Replaces everything after the enacting clause. Reinserts the provisions of the introduced bill with the following changes. In provisions amending the Local Government Taxpayers' Bill of Rights Act, creates a 7-year statute of limitations for utility taxes (currently, 4 years). In provisions amending the Illinois Municipal Code, provides that a public utility that is an electric utility may not provide customer-specific information. Provides that penalties for failure to respond to requests for information shall be assessed by the municipality, but may be reduced or vacated by the municipality or a court of competent jurisdiction upon demonstration by the public utility that the public utility's failure to provide the requested information resulted from excusable neglect. In provisions concerning a public utility's liability for premises that have been annexed to the municipality, provides that the utility shall only be liable beginning 60 days after the date that the municipality provided the public utility notice of the annexation. Adds provisions amending the Public Utilities Act. Provides that the Illinois Commerce Commission shall not consider: (i) costs associated with a municipal audit; (ii) any court costs, attorney's fees, or other fees incurred under certain provisions of the Illinois Municipal Code; (iii) unpaid utility taxes owed to a municipality; or (iv) any penalties or interest imposed by a municipality under certain provisions of the Illinois Municipal Code to be expenses for the purpose of determining any rate or charge. Senate Floor Amendment No. 2 Adds reference to: 220 ILCS 5/16-122 Makes changes to the bill as amended by Senate Amendment No. 1 to provide that the Illinois Commerce Commission shall not consider: (i) any court costs, attorney's fees, or other fees incurred under certain provisions of the Illinois Municipal Code; or (ii) any penalties or interest imposed by a municipality under certain provisions of the Illinois Municipal Code to be expenses for the purpose of determining any rate or charge (Senate Amendment No. 1 also includes costs associated with a municipal audit and unpaid utility taxes owed to a municipality in the list). Further amends the Public Utilities Act to provide that customer specific billing, usage, or load shape data may be provided to a unit of local government if the unit of local government is requesting the information for the purposes of an audit under specified provisions of the Illinois Municipal Code. House Floor Amendment No. 4 Deletes reference to: 220 ILCS 5/9-224.1 new Replaces everything after the enacting clause. Reinserts the provisions of the engrossed bill with changes. In provisions amending the Local Government Taxpayers' Bill of Rights Act, provides that a notice of determination of tax due or assessment (removing the limitation in the engrossed bill to utility taxes) may be issued more than 5 years (rather than 7 years in the engrossed bill) after the end of the calendar year for which the return or the period was filed or the end of the calendar year in which the return for the period was due, whichever occurs later. Provides that a timely performed audit or review shall toll the applicable 5-year period for a period of not more than 1 year. Makes other changes. In provisions amending the Illinois Municipal Code relating to a municipality's tax review of a public utility: specifies information that may be requested by the municipality related to premises-specific and other information used by the public utility to determine the amount of tax due to the municipality; revises provisions relating to information that may be collected related to the premises address for customer accounts; provides that the public utility shall attempt to resolve any questions or issues that arise in the tax review without disclosing any customer-specific information and provides that the public utility or municipality may pursue questions or issues before the Department of Revenue; modifies provisions relating to penalties that a public utility can face related to a tax review; modifies provisions relating to the public utility liability to the municipality for unpaid taxes; adds provisions relating to using a web portal rather than email to receive notice of annexations and boundary changes and provisions relating to the Department of Revenue developing and publishing a written process to be used by each public utility and each municipality that imposes a specified tax; and makes other changes. In provisions concerning the Public Utilities Act, makes changes in provisions concerning customer information. Effective immediately.