35 ILCS 640/2-9
Each delivering supplier who is required or authorized to collect the tax imposed by this Law shall make a return to the Department on or before the 15th day of each month for the preceding calendar month stating the following:
In making such return the delivering supplier may use any reasonable method to derive reportable "kilowatt-hours" from the delivering supplier's records.
If the average monthly tax liability to the Department of the delivering supplier does not exceed $2,500, the Department may authorize the delivering supplier's returns to be filed on a quarter-annual basis, with the return for January, February and March of a given year being due by April 30 of such year; with the return for April, May and June of a given year being due by July 31 of such year; with the return for July, August and September of a given year being due by October 31 of such year; and with the return for October, November and December of a given year being due by January 31 of the following year.
If the average monthly tax liability to the Department of the delivering supplier does not exceed $1,000, the Department may authorize the delivering supplier's returns to be filed on an annual basis, with the return for a given year being due by January 31 of the following year.
Such quarter-annual and annual returns, as to form and substance, shall be subject to the same requirements as monthly returns.
Notwithstanding any other provision in this Law concerning the time within which a delivering supplier may file a return, any such delivering supplier who ceases to engage in a kind of business which makes the person responsible for filing returns under this Law shall file a final return under this Law with the Department not more than one month after discontinuing such business.
Each delivering supplier whose average monthly liability to the Department under this Law was $10,000 or more during the preceding calendar year, excluding the month of highest liability and the month of lowest liability in such calendar year, and who is not operated by a unit of local government, shall make estimated payments to the Department on or before the 7th, 15th, 22nd and last day of the month during which tax liability to the Department is incurred in an amount not less than the lower of either 22.5% of such delivering supplier's actual tax liability for the month or 25% of such delivering supplier's actual tax liability for the same calendar month of the preceding year. The amount of such quarter-monthly payments shall be credited against the final tax liability of such delivering supplier's return for that month. An outstanding credit approved by the Department or a credit memorandum issued by the Department arising from such delivering supplier's overpayment of his or her final tax liability for any month may be applied to reduce the amount of any subsequent quarter-monthly payment or credited against the final tax liability of such delivering supplier's return for any subsequent month. If any quarter-monthly payment is not paid at the time or in the amount required by this Section, such delivering supplier shall be liable for penalty and interest on the difference between the minimum amount due as a payment and the amount of such payment actually and timely paid, except insofar as such delivering supplier has previously made payments for that month to the Department in excess of the minimum payments previously due.
If the Director finds that the information required for the making of an accurate return cannot reasonably be compiled by such delivering supplier within 15 days after the close of the calendar month for which a return is to be made, the Director may grant an extension of time for the filing of such return for a period not to exceed 31 calendar days. The granting of such an extension may be conditioned upon the deposit by such delivering supplier with the Department of an amount of money not exceeding the amount estimated by the Director to be due with the return so extended. All such deposits shall be credited against such delivering supplier's liabilities under this Law. If the deposit exceeds such delivering supplier's present and probable future liabilities under this Law, the Department shall issue to such delivering supplier a credit memorandum, which may be assigned by such delivering supplier to a similar person under this Law, in accordance with reasonable rules and regulations to be prescribed by the Department.
The delivering supplier making the return provided for in this Section shall, at the time of making such return, pay to the Department the amount of tax imposed by this Law.
Until October 1, 2002, a delivering supplier who has an average monthly tax liability of $10,000 or more shall make all payments required by rules of the Department by electronic funds transfer. The term "average monthly tax liability" shall be the sum of the delivering supplier's liabilities under this Law for the immediately preceding calendar year divided by 12. Beginning on October 1, 2002, a taxpayer who has a tax liability in the amount set forth in subsection (b) of Section 2505-210 of the Department of Revenue Law shall make all payments required by rules of the Department by electronic funds transfer. Any delivering supplier not required to make payments by electronic funds transfer may make payments by electronic funds transfer with the permission of the Department. All delivering suppliers required to make payments by electronic funds transfer and any delivering suppliers authorized to voluntarily make payments by electronic funds transfer shall make those payments in the manner authorized by the Department.
If any payment provided for in this Section exceeds the delivering supplier's liabilities under this Act, as shown on an original return, the Department may authorize the delivering supplier to credit such excess payment against liability subsequently to be remitted to the Department under this Act, in accordance with reasonable rules adopted by the Department.
Through June 30, 2004, each month the Department shall pay into the Public Utility Fund in the State treasury an amount determined by the Director to be equal to 3.0% of the funds received by the Department pursuant to this Section. Through June 30, 2004, the remainder of all moneys received by the Department under this Section shall be paid into the General Revenue Fund in the State treasury. Beginning on July 1, 2004, of the 3% of the funds received pursuant to this Section, each month the Department shall pay $416,667 into the General Revenue Fund and the balance shall be paid into the Public Utility Fund in the State treasury.
35 ILCS 640/2-9