California Code, Elections Code - ELEC § 2159

(a) Notwithstanding paragraph (1) of subdivision (b) of Section 2158, any person who, in exchange for money or other valuable consideration, assists another to register to vote by receiving the completed affidavit of registration from the elector, shall sign in his or her handwriting and affix directly on the affidavit of registration his or her full name, telephone number, and address, and the name and telephone number of the person, company, or organization, if any, that agrees to pay money or other valuable consideration for the completed affidavit of registration. Failure to comply with this section shall not cause the invalidation of the registration of the voter.

(b) Any person who in exchange for money or other valuable consideration assists another to register to vote by receiving the completed affidavit of registration from the elector, and knowingly misrepresents himself or herself as having helped register another to vote on a registration form is guilty of a misdemeanor, pursuant to Section 18108.1.