(1) Except as provided in s. 220.23(2)(c), if any amount of tax imposed by this chapter is not paid on or before the date, determined without regard to any extensions, prescribed for payment of such tax, interest shall be paid in accordance with the provisions of s. 220.807 on the unpaid amount from such date to the date of payment. (2) Interest prescribed by this section on any tax or penalty shall be deemed assessed upon the assessment of the tax or penalty to which such interest relates, and shall be collected and paid in the same manner as taxes. Any reference in this chapter to the tax imposed by this chapter shall be deemed a reference to interest imposed by this section.
(3) No interest shall be imposed upon the interest provided by this section.
(4) Interest shall be paid in respect to any penalty which is not paid within 20 days of the notice and demand therefor, but only for the period from the date of the notice and demand to the date of payment.
(5) If notice and demand is made for the payment of any amount due under this chapter, and if such amount is paid within 30 days after the date of such notice and demand, interest under this section on the amount so paid shall not be imposed for the period after the date of such notice and demand.
(6) Any tax, interest, or penalty imposed by this chapter which has been erroneously refunded and which is recoverable by the department shall bear interest computed as provided in s. 220.807 from the date of payment of such refund. (7) The department may settle or compromise interest imposed herein pursuant to s. 213.21. 
