(a)

1. (1) Unless it is shown that the failure is due to reasonable cause and not due to willful neglect, a penalty computed in accordance with paragraph (2) is hereby imposed in the case of failure to pay any of the following:

   1. (A) The amount shown as tax on any return on or before the date prescribed for payment of that tax determined with regard to any extension of time for payment.
   2. (B) Any amount in respect of any tax required to be shown on a return which is not so shown including an assessment made pursuant to Section 19051 within 15 days of the date of the notice and demand therefor.
   3. (C) The amount required to be paid by Section 19021, if applicable, that is not paid.
   4. (D) The amount required to be paid by Section 17941 or 23091, if applicable, that is not paid.
   5. (E) The amount required to be paid by Section 17948 or 23097, if applicable, that is not paid.

2. (2) The penalty imposed under paragraph (1) shall consist of both of the following:

   1. (A) Five percent of the total tax unpaid as defined in subdivision (c).
   2. (B) An amount computed at the rate of 0.5 percent per month of the “remaining tax” as defined in subdivision (d) for each additional month or fraction thereof not to exceed 40 months during which the “remaining tax” is greater than zero.
3. (3) The aggregate amount of penalty imposed by this subdivision shall not exceed 25 percent of the total unpaid tax and shall be due and payable upon notice and demand by the Franchise Tax Board. The tender of a check or money order does not constitute payment of the tax for purposes of this section unless the check or money order is paid on presentment.

(c) For purposes of this section, total tax unpaid means the amount of tax shown on the return reduced by both of the following:

1. (1) The amount of any part of the tax which is paid on or before the date prescribed for payment of the tax.
2. (2) The amount of any credit against the tax which may be claimed upon the return.