If parents have a custody/access agreement they can simply make a new agreement or change their existing agreement. If the parents cannot agree on the change either one can apply to court for a custody/access order. The court will then decide custody and access based on the best interests of the child. In determining this, one thing the court will consider is the current custody/access arrangement.
Changing Court Orders
A court order can only be changed by the court. If both parties agree on the change they can ask the court to change the order by consent of both parties. When parties cannot reach an agreement about a change to custody/access either party can ask the court to change the existing order. The Courts will not change a custody/access order unless the party asking for a change can show that there has been a significant change that affects the care of the child. The courts call this a material change. There must be a fundamental change in the child’s needs or in the parents’ ability to meet those needs since the order was made. A party cannot ask the court to change an order just because they do not agree with the original order.
Things like one party re-marrying or entering into a new relationship are not automatically grounds for asking for a change in custody/access. The party asking for the change would have to show that the new relationship significantly affected the child’s care. It also cannot be a change that would have been anticipated when the order was made. For example, a child getting older may not by itself be a significant change.
The change in circumstances that is material, is one that, if known at the time of the original order, would likely have resulted in different terms with regard to custody. Saskatchewan Court of Appeal
Once the party asking for a different order has shown that there is a change that affects the care of the child, the court will then be guided by the best interests of the child in deciding whether to make the requested change. The party asking for a change must show that the requested change is in the best interests of the child. The court will consider the same factors when determining the best interests of the child as they consider when a custody/access order is first made. The court will be guided by the belief that a child should have as much contact with both parents as is consistent with their best interests. And the courts will also consider the willingness of each parent to facilitate such contact with the other parent, even in difficult situations.