If you haven't experienced it yourself, you probably have a friend who has.
The threat that the other parent will take the child, move and you will never see them again.
This is a common threat to hear but it can also be a simple question such as, do I have to notify another parent if I move? If you were hoping for a simple answer, then you're about to be disappointed.
If parents have entered into a legal custody agreement then the language in the agreement will tell you what the answer is.
If the language states that parents may not move out of the county without prior notification, then that's what is required.
If the language states nothing about moving but states only significant changes can be grounds to redo the order, then a parent moving would be grounds to take another look.
If there is no agreement between the parents then there is no agreement to break by moving.
The language of your custody agreement will dictate what steps you need to take.
But if you don't have an agreement then there is no agreement to keep or break.
If that sounds wrong then think of it from a contractual point of view and not from a moral point of view.
Morally it seems that parents should tell each other where they are going to move and make plans accordingly.
Unfortunately morality is not the basis for custody agreements.
Courts cannot enforce agreements that don't exist.
If a parent moves to another state when no previous agreement exists, then the other parent would be forced to open a case in the place where the child resides, not where they came from.
The logistical element alone could make it nearly impossible to get a workable agreement.
Remember that the courts primary directive is to protect the "interest of the child" and the most basic interest the child has is the relationship with their parents.
What is the moral of this story? The moral is that parents need an agreement to protect them and their relationships with their children.
Simple language can prevent a terrible tragedy like moving away without notification, or at least give you teeth if it happens.