With prenuptial agreements, there are some things you can and cannot do. One of the things you're unable to do is to include your child's custody plan ahead of time.
There are a few good reasons for this. The first reason is that you may not have children at the time of writing the prenuptial agreement, so setting up a custody plan doesn't make sense and isn't based on your child's needs.
Another reason that it's not allowed to include custody is that there is no way to know what your child's needs are at the time of divorce until you go through it. Your child might feel closer to mom or dad, or there could have been arguments or fights that change the way you feel about custody.
Your financial situation may change in the future, too, so developing a custody plan based on your finances before marriage isn't a good idea.
What will a judge do if custody arrangements are included in a prenuptial agreement?
Since the arrangements aren't allowed to be in the prenuptial agreement, the judge will not allow them to be used as part of your divorce. In some cases, a judge may choose to invalidate the entire prenuptial agreement instead of just a single part, so it is best to work with your attorney to create a legally binding prenuptial agreement that does not have items it should not contain. Mistakes in the prenuptial agreement could lead to it being thrown out, resulting in you and your spouse having to start from scratch with your property division and other factors involved in your divorce.