California Revenue & Taxation Code
Cal. Rev. & Tax. Code § 7155
# (a)
Any person who, for the purpose of evading the payment of taxes due under this part, knowingly fails to obtain a valid permit prior to the date on which the first tax return is due shall be liable for a penalty of 50 percent of any tax determined to be due for the period during which the person engaged in business in this state as a seller without a valid permit.
# (b)
This section shall not apply to any person whose measure of tax liability over the period during which he or she was engaged in business in this state as a seller without a valid permit averaged one thousand dollars ($1,000) or less per month.
# (c)
This section shall not apply to the amount of taxes due on the sale or use of a vehicle, vessel, or aircraft, if the amount is subject to the penalty imposed by Section 6485.1 or Section 6514.1.
Source: view the official text