Yes, there are grounds for changing a court ordered amount of support. I wonder (just from the way you asked) whether you actually have gotten a court’s order for support, or if the other parent is asking for a certain amount, without any court involvement yet? To protect your rights and interests in support payments, you might get some affordable legal help, “ASAP.” Here’s one legal aid source for you: http://lawhelpca.org/.
 
In fact, courts keep an eye on any child custody case, to make sure the best interests of a child are front and center for as long as they are minors or dependent. So, among the reasons to change a support amount are the many financial ways that paying “too much” might negatively affect your relationship with your child…for example, not being able to go visit the child. All told, there are actually almost a dozen “principles” that affect how much child support should be paid. Let’s look at those ideas in a minute.
 
First, though, be ready to learn, and then to be able to apply or change the typical California Support rules and amounts. Later, I’ll give you a link to a support calculator.
 
Now, as  I mentioned, there are at least a dozen key ideas in setting support. You should know these principles, to get a good idea of “both sides” of how to set child support. http://www .leginfo.ca.gov/cgi-bin/displaycode?section=fam&group=04001-05000&file=4050-4076.
 
The Principles Of Setting The Correct Amount Of Support
 
I suggest you can use these as a sort of checklist, indicating whether it favors your paying more or less. You’ll see one important point is what the other parent contributes, and these principles also apply to them. This is because it's the interests of the child that matter most.
 
(a) A parent's first and principal obligation is to support his or her minor children according to the parent's circumstances and station in life.
(b) Both parents are mutually responsible for the support of their
children.
(c) The guideline takes into account each parent's actual income and level of responsibility for the children. Here’s a calculator just to see where you fall in the guidelines: https://www.cse.ca.gov/Child Support/cse/ guidelineCalculator.
(d) Each parent should pay for the support of the children according to his or her ability.
(e) The guideline seeks to place the interests of children as the state's top priority.
(f) Children should share in the standard of living of both parents. Child support may therefore appropriately improve the standard of living of the custodial household to improve the lives of the children.
(g) Child support orders in cases in which both parents have high levels of responsibility for the children should reflect the increased costs of raising the children in two homes and should minimize significant disparities in the children's living standards in the two homes.
(h) The financial needs of the children should be met through private financial resources as much as possible. Is the other parent receiving state or federal aid?
(i) It is presumed that a parent having primary physical responsibility for the children contributes a significant portion of available resources for the support of the children. Have a chart showing your suggested per cent of contribution.
(j) The guideline seeks to encourage fair and efficient settlements of conflicts between parents and seeks to minimize the need for litigation.
(k) The guideline is intended to be presumptively correct in all cases, and only under special circumstances should child support orders fall below the child support mandated by the guideline formula.
 
The biggest block to many, fairer decreases in support is the final principle, and we’ll look at it in more detail, in the next section:
 
(l) Child support orders must ensure that children actually receive fair, timely, and sufficient support reflecting the state's high standard of living and high costs of raising children compared to other states.
 
The Importance Of Physical Custody
 
Most courts once rested their support decisions on who had physical custody, and the non-custodial parent’s “earning capacity.” Now, the perceived and real costs of living in California still means the non-custodial parent often pays much more than is fair to the custodial parent’s home costs---often, more than the non-custodial parent can afford for their own well-being.
 
Here’s a “Modification Petition” guide, useful to ask a California court to emphasize your “Change In Circumstances,” in order to pay less than the guidelines. http://www. courts.ca.gov/1196.htm.