Revenue and taxation; interest rate computations; state tax liabilities; effective date.

HB 2730 modifies Oklahoma's tax interest rates and penalties for late payments. It sets interest on overdue state taxes at 1.25% per month (based on the Wall Street Prime rate plus 3%) and establishes specific penalty timelines: 10% penalties apply after 15 days for sales/use taxes or 30 days for other taxes, unless paid within 60 days of notice. The bill also updates refund interest deadlines, requiring the Tax Commission to pay interest on delayed refunds within 30 days for electronic filings or 90 days for paper returns. These changes apply to all delinquent accounts as of the bill's effective date, November 1, 2025.