HI SB1356

Prohibits stacking of tax penalties by preventing penalties for substantial understatements, property overvaluations/undervaluations, and erroneous refund claims from being imposed on the same underpayment if another penalty has already been assessed.

Changes tax filing and payment deadlines from the 20th day of each month to the last day of each month for general excise tax, hotel occupancy tax, use tax, fuel tax, liquor tax, cigarette and tobacco tax, and insurance premium tax.

Aligns Hawaii tax penalty provisions with federal Internal Revenue Code standards, limiting taxpayers to a single 20 percent penalty per underpayment regardless of multiple types of prohibited conduct.

Applies to taxable years beginning after December 31, 2010, with the deadline changes effective January 1, 2030, and all other provisions effective July 1, 2030.