Child support is modifiable in Florida. Modifying child support requires that a substantial change in circumstance. Simply not having a job does not automatically mean that a party qualifies for modification, the party must prove that she/he was fired or laid off from the job and it was not voluntary on his/her part. Also, if a party leaves a job for a less paying one, then that is considered voluntary underemployment and does not qualify for grounds of child support modification.
Florida calculates child support based on incomes of the parties and modifying that number requires a significant deviation (up or down) in the incomes of the parties. The increase or decrease of income, if significant enough, can lead to a change a child support in regards to the calculation. however, a small deviation, such as a 5% increase or decrease would not significantly impact the guidelines and therefore does not give rise to a modification.
Both parties are allowed to ask for a modification. This allows both parties access to the courts so that an increase or decrease in child support can be properly assessed based on the present situation. This is helpful for those that get divorced or have a paternity action while the children are young because over time both parties will most likely make more money and child support should be inflated to keep up with the households the child lives in the majority of the time. Also, if the child decides to reside with the each parent equally, then child support should be modified to reflect that time-sharing differential.
If you have questions regarding child support, you should speak with a family law attorney to better understand your rights and options.