In order to change the amount of child support you are receiving, you must first request the change through a formal motion in court. The court will then decide if there are sufficient grounds to change the amount. You will usually have to show "changed circumstances", in almost all jurisdictions, from the facts from the circumstances at the time the last order was entered.

Some instances that are considered "changed circumstances" that may result in support being increased are:
- A large increase in income
- The child's needs have grown (e.x. the child becomes ill or disabled)
- Passage of time

Some instances that are considered "changed circumstances" that may result in support being decreased are:
- The custodial parent inherits money, gets a large raise, or has in increase in money
- The paying parent loses his or her job