Legal Question in Family Law in Washington

The word "custody" has an unclear meaning, as it is generally not used in Washington. I also don't know what you mean by "transfer custody." I will assume that you have a court ordered temporary parenting plan or residential schedule (that means the court entrusted the care, welfare and health of the child to you), and that you are thinking of something more than baby sitting or childcare services. In that case you can transfer "custody" only by court order.