Utah Code § 81-5-304: Rules for declaration and denial of paternity.

(1)

(a) A declaration of paternity and a denial of paternity shall be contained in a single document.

(b) If the declaration of paternity and the denial of paternity are both necessary, neither is valid until both are signed and filed.

(2) A declaration of paternity or a denial of paternity may not be signed before the birth of the child.

(3) Subject to Subsection (1), a declaration of paternity or denial of paternity takes effect on the birth of the child or the filing of the document with the Office of Vital Records and Statistics, whichever occurs later.

(4) A declaration of paternity or denial of paternity signed by a minor and by the minor's parent or legal guardian is valid if the declaration of paternity or the denial of paternity is otherwise in compliance with this chapter.