It depends on the guidelines for your particular state. If you're speaking of an increase in child support due to an increase in your income, that can happen if the CP files a motion for modification with the court that issued the original order. In my state, in order to get a child support order modified, the petitioner must show an appreciable change in circumstances. A substantial increase in income, such as may occur with getting a new job more lucrative than your previous one, would constitute such a change in circumstance.