Child support does not automatically modify when there is a change in circumstances that warrants it, a party must file a supplemental petition for modification of it. When there has been a substantial change in circumstances warranting a modification of child support a parent needs to file a supplemental petition for modification of child support as soon as possible after the change has occurred as a court can only modify child support from the date of filing of the supplemental petition.
Where courts have attempted to modify child support from before the date of the supplemental petition they have been reversed on appeal. For instance, in Tatum v. Tatum the Fifth District Court of Appeals for the State of Florida reversed the trial court’s decision to retroactively modify child support to a date prior to the date of the filing of the petition for modification.
If you need to seek an upward or downward modification of child support you need to get your supplemental petition filed as soon as possible after the substantial change in circumstances has occurred so that it the change can be retroactive to as close to the date of the change warranting the modification as possible.