Cal. Rev. & Tax. Code § 46251

If any feepayer fails to make a return, the board shall make an estimate of the amount of fee to be paid. The estimate shall be made for the period or periods in respect to which the person failed to make a return and shall be based upon any information which is in the board’s possession or may come into its possession. Upon the basis of this estimate, the board shall compute and determine the amount of fee or other amount required to be paid to the state, adding to the sum thus arrived at a penalty equal to 10 percent thereof. One or more determinations may be made for one or more than one period. When a business is discontinued, a determination may be made at any time thereafter, within the periods specified in Section 46203, as to liability arising out of that business, irrespective of whether the determination is issued prior to the due date of the liability as otherwise specified in this part.