Even if one parent has sole custody, it's a good idea for each parent to sign the consent letter indicating their permission, especially if the other parent has visiting rights. The court may decide that only one parent needs to give permission for treatment if they have "sole custody". If one parent does not give permission, then the other parent cannot be forced to go through with the treatment. Custody means who gets decision-making power over important things like education, health care, and religion. In most cases, parents work together when making these decisions for their children. However, if there is a disagreement about what role each parent should play in the child's life, then the court can decide who makes those decisions. For example, one parent might have "sole custody" of the child while the other parent has "visiting rights." "Sole custody" means that one parent has the majority of decisions made regarding the child's upbringing. This parent is usually called the "custodial parent". Even if one parent has "sole custody", they still need to give permission for treatment if the other parent wants to use it. The court may change who has "sole custody" if there is a change in circumstances such as divorce or death of a spouse. It is best to talk with your lawyer about how shared custody works in your situation.