California Code, Revenue and Taxation Code - RTC § 24634

(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 Sections 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.