Cal. Family Code § 3423 : California Family Code — Custody Of Children — Jurisdiction — Jurisdiction of California court to modify determination made by court of another state Date: 7 Sep 2016 TEXT PDF Current through the 2016 Legislative Session Except as otherwise provided in Section 3424, a court of this state may not modify a child custody determination made by a court of another state unless a court of this state has jurisdiction to make an initial determination under paragraph (1) or (2) of subdivision (a) of Section 3421 and either of the following determinations is made: (a) The court of the other state determines it no longer has exclusive, continuing jurisdiction under Section 3422 or that a court of this state would be a more convenient forum under Section 3427. (b) A court of this state or a court of the other state determines that the child, the child's parents, and any person acting as a parent do not presently reside in the other state. Ca. Fam. Code § 3423 EFFECTIVE 1/1/2000. Added October 10, 1999 (Bill Number: AB 673) (Chapter 1004).