California Code, Revenue and Taxation Code - RTC § 43160

Every person who is required to file the returns and make the payments specified in Section 43152.13 shall, upon transfer or discontinuance of operations, file closing returns on forms prescribed by the California Department of Tax and Fee Administration. The closing returns shall be due and payable on the last day of the month following the end of the quarterly period in which the transfer or discontinuance takes place.