CA AB2120

Requires the Franchise Tax Board to assess interest on amounts not paid by the due date unless the failure to pay is due to reasonable cause and not willful neglect.

Applies interest at the adjusted annual rate established under Section 19521, computed from the due date until the amount is paid.

Maintains existing liability standards for persons who fail to withhold required tax amounts, with penalties of either the amount actually withheld or taxes due from the taxpayer, whichever is greater.

Adds the "willful neglect" standard as a requirement to qualify for the reasonable cause exception for interest assessments on late withholding payments.