Cal. Business and Professions Code § 6147.5

(a) Sections 6147 and 6148 shall not apply to contingency fee contracts for the recovery of claims between merchants as defined in Section 2104 of the Commercial Code, arising from the sale or lease of goods or services rendered, or money loaned for use, in the conduct of a business or profession if the merchant contracting for legal services employs 10 or more individuals. (b) (1) In the instances in which no written contract for legal services exists as permitted by subdivision (a), an attorney shall not contract for or collect a contingency fee in excess of the following limits: (A) Twenty percent of the first three hundred dollars ($300) collected. (B) Eighteen percent of the next one thousand seven hundred dollars ($1,700) collected. (C) Thirteen percent of sums collected in excess of two thousand dollars ($2,000). (2) However, the following minimum charges may be charged and collected: (A) Twenty-five dollars ($25) in collections of seventy-five dollars ($75) to one hundred twenty-five dollars ($125). (B) Thirty-three and one-third percent of collections less than seventy-five dollars ($75).