As with child and spousal support, in order to obtain an Order varying your current custody or access arrangement, you must prove that there has been a material change in circumstances.  In order to successfully obtain a variation order regarding custody or access, the change that occurred must be material, and must have also affected, or be likely to affect the best interests of the child. The change must also be one that was not foreseen at the time the initial order or variation was made. You cannot use a motion to change custody/access as an avenue to appeal the initial decision.

When parents move on to form new relationships, their new spouses can sometimes assume the role of parent to a child from the previous relationship, even though they are not the biological parent. This is known in law as standing "in loco parentis" which means "standing in place of a parent." In these situations, a parent-child relationship can form, which may give rise to an obligation to support that child.