Cal. CCP § 425.30

(a) In an action for collection of consumer debt, common counts may not be used. For purposes of this section, a “common count” includes, but is not limited to, a claim for recovery of any of the following:

(1) An open book account for money due.

(2) An account stated in writing by and between plaintiff and defendant in which it was agreed that defendant was indebted to plaintiff.

(3) Money had and received by defendant for the use and benefit of plaintiff.

(4) Work, labor, services, and materials rendered at the special instance and request of defendant and for which defendant promised to pay plaintiff.

(5) Goods, wares, and merchandise sold and delivered to defendant and for which defendant promised to pay plaintiff.

(6) Money lent by plaintiff to defendant at defendant’s request.

(7) Money paid out, laid out, and expended to or for defendant at defendant’s special instance and request.

(b) For purposes of this section, “consumer debt” means any obligation or alleged obligation, incurred on or after July 1, 2024, of a consumer to pay money arising out of a transaction in which the money, property, insurance, or services that are the subject of the transaction are primarily for personal, family, or household purposes and where the obligation to pay appears on the face of a note or in a written contract.

(c) In an action under this section for the collection of consumer debt brought by a debt buyer, as defined in Section 1788.50 of the Civil Code, the debt buyer shall also comply with Section 1788.58 of the Civil Code and the remaining provisions of Title 1.6C.5 (commencing with Section 1788.50) of Part 4 of Division 3 of the Civil Code.