Determination of interest on deficiencies.

(1) Notwithstanding any other provision of law, the annual rate of interest applicable to tax payment deficiencies that arise on or after January 1, 2000, shall be the adjusted rate established by the executive director of the department under subsection (2), unless a lower rate for the particular tax is specifically provided for in law, in which case the lower rate applies. This annual rate of interest applies to all taxes enumerated in s. 213.05.

(2) If the adjusted prime rate charged by banks, rounded to the nearest full percent, plus 4 percentage points, during either:

(a) The 6-month period ending on September 30 of any calendar year, or

(b) The 6-month period ending on March 31 of any calendar year

differs from the interest rate in effect on either such date, the executive director of the department shall, within 20 days, establish an adjusted rate of interest equal to such adjusted prime rate plus 4 percentage points.

(3) An adjusted rate of interest established under this section becomes effective:

(a) On January 1 of the succeeding year, if based upon the adjusted prime rate plus 4 percentage points for the 6-month period ending on September 30; or

(b) On July 1 of the same calendar year, if based upon the adjusted prime rate plus 4 percentage points for the 6-month period ending on March 31.

(4) As used in this section, the term “adjusted prime rate charged by banks” means the average predominant prime rate quoted by commercial banks to large businesses, as determined by the Board of Governors of the Federal Reserve System.

(5) Once established, an adjusted rate of interest remains in effect until further adjusted under subsection (2).