Revenue and Taxation Code section 24634
(a)
A return for a period of less than 12 months (referred to in this article as “short period”) shall be made under any of the following circumstances:(1)
When the taxpayer, with the approval of the Franchise Tax Board, changes its annual accounting period. In such a case, the return shall be made for the short period beginning on the day after the close of the former taxable year and ending at the close of the day before the day designated as the first day of the new taxable year.(2)
When the taxpayer is in existence during only part of what would otherwise be its taxable year, except if the taxpayer’s existence terminates as a result of a reorganization described in Section 368(a)(1)(F) of the Internal Revenue Code.(3)
When the Franchise Tax Board terminates the taxpayer’s taxable year under Section 19081 and 19082 (relating to tax in jeopardy).(4)
When the taxpayer is required to make a federal return for a period of less than 12 months.(b)
This section shall apply whether or not a federal return is required to be filed for a period of less than 12 months.(c)
If a return is required to be filed under this section for a period of less than 12 months, that period shall be deemed to be a taxable year.
Source:
Section 24634, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=RTC§ionNum=24634. (accessed May 26, 2025).