Cal. Health & Safety Code § 112775

If at the end of the calendar year, or at the end of any canning season of less than three consecutive months the deposit made by any licensee under this chapter is greater than the actual cost prorated to the licensee, the difference shall be refunded if requested by the licensee in accordance with law. If the difference is not so refunded, it shall be credited toward the required deposit for the next calendar year or canning season.