When the divorce judgment is handed down, it's binding. You must adhere to the court order. For instance, even if you wanted sole custody of your child, if the order specifies that custody should be shared between you and your ex, you have to honor that. This can be hard for some parents to accept, feeling that they know the situation better than the judge, but violating a court order is illegal.
The good news is that changing circumstances may warrant a modification. While the order is legally binding, do not assume it lasts forever.
The key is to look into the proper legal steps you need to take to get the order modified in court. Do not take things into your own hands, even if you think the change is warranted and will be supported by a judge. You need that support first.
For example, maybe the court ordered you to make monthly child support payments of $2,500. A year after that order comes down, the company downsizes and cuts your position. You get a new job, but it pays you half of what you earned before.
You can absolutely present evidence of the financial change and ask the court to modify the agreement to reflect your new situation. What you cannot do, though, is stop making your child support payments early. Until you get the ruling in your favor, you are still obligated to abide by the original order.
As you can see, it is sometimes very important to learn about your rights and the legal modification process quickly. Be sure you know exactly what steps to take.
Source: FindLaw, "Appeals and Motions to Modify the Divorce Judgment," accessed April 20, 2018