ACT QUICKLY. You must act now, as there are only a few situations where child support will be modified in the past, usually any modification will start from the date that the complaint to modify was filed.
SIMPLE TERMS. In simple terms the three main factors in calculating child support are your income the other parent's income and the number of overnights the children are with each parent. The standard for a modification of child support is whether there is a substantial and material change in circumstances. In relation to child support it generally means a change in circumstances that would be about a 10% or more change in child support. Every judge has a different opinion of that standard, as there is no numerical definition of what is a substantial and material circumstance to warrant a change in child support.
DETAILS. Often times it is the details that can create an increase or decrease when setting the amount for child support. Details such as (this is not an all-inclusive list, for that see an attorney):
INCOME. What is income is not a simple question, and a good attorney can find a way to make sure that income is counted correctly.
CONTINUING SUPPORT. So many child support orders do not include an automatic reduction when the oldest child reaches 18 or as old as 19 if not graduated from high school. In this situation I have seen Child Support Services continue to collect the same amount until all children reach
18 or as old as 19 if not graduated from high school. If your child support order does not include an automatic reduction then you need to see an attorney immediately.
OTHER CHILDREN. If you have children that you are paying support or that live with you then that needs to be accounted for. After-born children do not count but that is fairly technical evaluation and your attorney can assist you.
HEALTH INSURANCE. If health insurance is not accounted for properly in your child support order than you might need to see an attorney to make sure it is properly divided.
TAX DEDUCTION. The IRS rules change every year and the rules are so different for declaring a child as a dependent, the head-of-household exemption, the Earned Income Credit, the Earned Income Tax Credit, and the Additional Child Tax Credit. The child support guidelines as currently written account for the tax dependency exemption and the earned income credit but not the rest of the tax benefits, also the earned income credit disappears at age 17 and can be adjusted for then as well. You will need to see an attorney to properly allocate these benefits.
IMPUTING EARNINGS. If you or the other parent doesn't work full-time or are somehow underemployed the Court may impute earnings to you or the other parent under those circumstances.
NUMBER OF OVERNIGHTS. Oddly enough a lot of times the number of overnights are counted wrongly or even differently by different attorneys and can adjust child support.
ABATEMENT. If you have less than 25% of the overnights then you can get a reduction when the children are with you for a long period of time.
JUDGES GREATLY DIFFER ON THE DETAILS. Each of the above sections could be the subject of their own post, and very likely will be. Judges are so different in how they deal with the above topics that it is extremely important to talk to an attorney with experience. For example I have seen judges set someone's income for child support purposes with the highest paid job that that person had, and I have seen other judges set someone's income at their current earnings even if they quit being a six figure CEO to wash cars at a carwash.