Amends the Use Tax Act and the Retailers' Occupation Tax Act. Provides that, if a retailer inadvertently collects from a purchaser the entire 6.25% rate of tax on a sales tax holiday item, and if the retailer does not refund the excess tax proceeds to the purchaser, then the retailer shall remit those proceeds to the Department of Revenue in accordance with rules adopted by the Department of Revenue. Amends the Uniform Penalty and Interest Act. Provides that no penalties or interest shall be imposed under the Act for failure to pay a tax under the Use Tax Act or the Retailers' Occupation Tax Act on tangible personal property that is sold between August 5, 2022 and August 14, 2022 if (i) the failure to pay the tax was due to the taxpayer's mistaken belief that the item was a sales tax holiday item and (ii) the taxpayer made a good faith effort to comply with the requirements of the sales tax holiday. Amends the Illinois Administrative Procedure Act to provide for emergency rulemaking. Effective immediately.