California Code, Family Code - FAM § 7573

(a) The following persons may sign a voluntary declaration of parentage to establish the parentage of the child:

(b) A voluntary declaration of parentage shall be in a record signed by the woman who gave birth to the child and by either the only possible genetic parent other than the woman who gave birth or the intended parent of a child conceived through assisted reproduction, and the signatures shall be attested by a notary or witnessed.

(c) Except as provided by Section 7580, a voluntary declaration of parentage takes effect on the filing of the document with the Department of Child Support Services.

(d) Except as provided in Sections 7573.5, 7575, 7576, 7577, and 7580, a completed voluntary declaration of parentage that complies with this chapter and that has been filed with the Department of Child Support Services is equivalent to a judgment of parentage of the child and confers on the declarant all rights and duties of a parent.

(e) The court shall give full faith and credit to a voluntary declaration of parentage effective in another state if the declaration was in a signed record and otherwise complies with the law of the other state.

(f) This section shall become operative on January 1, 2020.