Cal. Rev. & Tax. Code § 30207

Except in the case of fraud, intent to evade the tax, or failure to make a report or return, every notice of a deficiency determination shall be served within three years after the 25th day of the month following the month for which the amount should have been paid or the report or return was due, or within three years after the report or return was filed, whichever period expires later. In the case of failure to make a report or return, the notice of determination shall be served within eight years after the date the report or return was due.