Family Code § 7573.5
CHAPTER 3. Establishment of Parentage by Voluntary Declaration
(a) A voluntary declaration of parentage is void if, at the time of signing, any of the following are true:
(1) A person other than the woman who gave birth to the child or a person seeking to establish parentage through a voluntary declaration of parentage is a presumed parent under Section 7540 or subdivision (a), (b), or (c) of Section 7611.
(2) A court has entered a judgment of parentage of the child.
(3) Another person has signed a valid voluntary declaration of parentage.
(4) The child has a parent under Section 7613 or 7962 other than the signatories.
(5) The person seeking to establish parentage is a donor pursuant to Section 7613.
(6) The person seeking to establish parentage asserts that the person is a parent under Section 7613 and the child was not conceived through assisted reproduction.
(b) In an action in which a party is seeking a determination that a voluntary declaration of parentage is void under this section, notice shall be provided pursuant to Section 7635.