When a Welfare and Institutions Code section 388 petition raises notice issues, a separate showing of best interests of the child is not required to warrant an evidentiary hearing. The minor came to the Agency’s attention in October 2018. Father’s name was listed on the section 300 petition, but his whereabouts were unknown. In subsequent reports, the Agency stated that a search was conducted for father, but the reports included no description of any search efforts. At the time of the six-month review hearing, father’s whereabouts, at a California State Prison, finally became known. Father filed a section 388 petition requesting that all prior findings be set aside because father was not notified of those proceedings. The juvenile court denied father’s section 388 motion, finding that father had shown changed circumstances by his recent release from prison, but had failed to meet the “best interests of the child” prong of the 388 petition. Father appealed the denial of the 388 petition and sought extraordinary relief from the order setting a section 366.26 hearing. The appellate court vacated the prior orders with direction to the juvenile court to conduct an evidentiary hearing on the 388 petition. Due process requires that a parent is entitled to notice that is reasonably calculated to apprise him or her of the dependency proceedings and afford him or her an opportunity to object. A parent may raise an Agency’s failure to provide him with adequate notice through a petition under section 388. When a section 388 petition is based on lack of notice, a separate showing of best interest is not required because a judgment that is proven void due to lack of due process notice suffers from a jurisdictional defect. Here, the trial court abused its discretion in denying father an evidentiary hearing on his section 388 petition because father sufficiently stated a notice violation where the record raised the possibility that the Agency failed to use due diligence to locate him. The error was not harmless because father had a relationship with the minor, and incarcerated parents are entitled to reunification services.