Cal. Rev. & Tax. Code § 19011.5

(a) All payments required by an individual under this part, regardless of the taxable year to which the payments apply, made on or after January 1, 2009, shall be electronically remitted to the Franchise Tax Board in the form and manner prescribed by the Franchise Tax Board, once any of the following conditions are met by an individual:
1. (1) Any installment payment of estimated tax made pursuant to this part in excess of twenty thousand dollars ($20,000), or any payment made pursuant to Section 18567 with regard to an extension of time to file that exceeds twenty thousand dollars ($20,000), for any taxable year beginning on or after January 1, 2009.
2. (2) The total tax liability exceeds eighty thousand dollars ($80,000) in any taxable year beginning on or after January 1, 2009. For purposes of this section, total tax liability shall be the total tax liability as shown on the original return, after any adjustment made pursuant to Section 19051.
(b) A taxpayer required to electronically remit payment to the Franchise Tax Board pursuant to this section may elect to discontinue making payments electronically where the threshold requirements set forth in paragraphs (1) and (2) of subdivision (a) were not met for the preceding taxable year. The election shall be made in a form and manner prescribed by the Franchise Tax Board.
(c) Any taxpayer required to electronically remit payment pursuant to this section who makes payment by other means shall pay a penalty of 1 percent of the amount paid, unless it is shown that the failure to make payment as required was for reasonable cause and was not the result of willful neglect.
(d) Any taxpayer required to electronically remit payments pursuant to this section may request a waiver of those requirements from the Franchise Tax Board. The Franchise Tax Board may grant a waiver only if it determines that the particular amounts paid in excess of the threshold amounts established in this section were not representative of the taxpayer’s tax liability. If the Franchise Tax Board grants a waiver to a taxpayer, the waiver shall be in writing, and subsequent electronic remittances shall be required only on those terms set forth in the written waiver.
(e) For purposes of this section, Chapter 3.5 (commencing with Section 11340) of Part 1 of Division 3 of Title 2 of the Government Code shall not apply to any standard, criterion, procedure, determination, rule, notice, or guideline established or issued by the Franchise Tax Board pursuant to subdivision (a).
(f) For purposes of this section, both of the following shall apply:
1. (1) “Electronically remit” means to send payment through use of any of the electronic payment applications provided by the Franchise Tax Board, including, but not limited to, a pay by phone option, when made available by the Franchise Tax Board.
2. (2) “Pay by phone” means a method that allows a taxpayer to authorize a transfer of funds from a financial institution using telephonic technology.