In most states the parents of a minor child may agree to the amount of child support, and courts encourage the parents to do so. But the court will generally review the agreed amount of child support and determine whether it is in the best interest of the child before signing a child support order. And if the parents later agree to change the amount of or need for child support, they should return to court and get a signed order that reflects the agreed or changed amount, as only the court may change the legal obligation under a child support order.

In Virginia, parents of a minor child can negotiate and agree upon the amount of child support. Virginia courts encourage such agreements as they often serve the best interests of the child and can expedite the legal process. However, any agreement on child support must be reviewed and approved by a court to ensure that it meets the child's needs and complies with state guidelines. The court will consider various factors, including each parent's income, the child's needs, and any special circumstances. If parents wish to modify an existing child support order, they must petition the court for a review. The court will then evaluate the request for modification based on changes in circumstances, such as a change in income, employment status, or the needs of the child. Only a court can legally alter the obligations set forth in a child support order, and any informal agreements between parents without court approval are not enforceable under Virginia law.