(35 ILCS 405/8) (from Ch. 120, par. 405A-8)
    Sec. 8. Penalties for failure to file tax return or to pay tax.
    (a) Failure to file return. In case of failure to file any return required under this Act with the Attorney General by the due date, unless it is shown that the failure to file is due to a reasonable cause, there shall be added to the amount required to be shown as tax on the return 5% of the amount of that tax (or 5% of the additional tax due in the case of a supplemental return) if the failure is for not more than one month from the due date, with an additional 5% for each additional month or fraction of a month thereafter during which the failure to file continues, not exceeding in the aggregate 25% of the tax or, in the case of a supplemental return, 25% of the additional tax.
    (b) Failure to pay tax. In the case of failure to pay the amount of tax shown due on any return required under this Act on or before the due date for payment of that tax, unless it is shown that the failure to pay is due to reasonable cause, there shall be added to the unpaid amount of the tax 0.5% of that unpaid amount if the failure is for not more than one month from the due date, with an additional 0.5% for each additional month or fraction of a month thereafter during which the failure to pay continues, not exceeding in the aggregate 25% of the unpaid amount.
    (c) Extensions of Time.
        (1) Internal Revenue Service Extensions. If the date
    
for filing the federal return or the date for payment of the federal transfer tax is extended by the Internal Revenue Service, the filing of the return and payment of the tax imposed by this Act shall be due on the respective date specified by the Internal Revenue Service in granting a request for extension. If the request for extension is granted by the Internal Revenue Service, the person required to file the Illinois transfer tax return shall furnish the Attorney General with a copy of the request for extension showing approval of the extension by the Internal Revenue Service. If a request for extension of time to file the federal return is denied by the Internal Revenue Service, no penalty shall be due under this Act if the return required by this Act is filed within the time specified by the Internal Revenue Service for filing the federal return. If a request for extension of time to pay the federal transfer tax is denied by the Internal Revenue Service, no penalty shall be due under this Act if the tax is paid within the time specified by the Internal Revenue Service for paying the federal transfer tax.
        (2) Attorney General Extensions. The person or
    
persons required to file the Illinois transfer tax return and to pay the Illinois transfer tax may apply to the Attorney General for an extension of time to file the Illinois transfer tax return or to pay the Illinois transfer tax. The application must establish reasonable cause why it is impossible or impractical to file a reasonably complete return or to pay the full amount of tax due by the due date. The Attorney General may for reasonable cause extend the time for filing the return or paying the tax for a reasonable period from the date fixed for filing the return or paying the tax.
    (d) Waiver of Penalties.
        (1) Internal Revenue Service Waiver. If the Internal
    
Revenue Service waives the penalty provided in the Internal Revenue Code for failure to timely file the federal return or the penalty for failure to timely pay the federal transfer tax liability, such waiver or waivers shall be deemed to constitute reasonable cause for purposes of this Section.
        (2) Attorney General Waiver. The Attorney General
    
may waive the penalty or penalties for failure to file or pay for reasonable cause, notwithstanding the failure of the Internal Revenue Service to waive the penalty or penalties for failure to timely file the federal transfer tax return or to pay the federal transfer tax.
(Source: P.A. 93-30, eff. 6-20-03.)