Quick answer: In North Carolina, child support can be modified at any time on a motion showing changed circumstances. For an order at least three years old, a 15% difference from the guideline amount is presumed to be a substantial change. Past-due payments are vested and cannot be reduced unless a motion was filed before they were due.
This North Carolina child support modification calculator applies G.S. 50-13.7. Enter your current order and the amount the guidelines give today (you can get it from the North Carolina child support calculator), say whether the order is at least 3 years old, and it shows whether the 15% presumption applies, the monthly gap and what it adds up to after filing.
North Carolina child support modification at a glance
| Rule | What North Carolina says |
|---|---|
| Standard | An order for support of a minor child may be modified or vacated at any time, on a motion in the cause and a showing of changed circumstances (G.S. 50-13.7(a)) |
| 15% presumption | Guidelines: for an order at least three years old, a difference of 15% or more from the guideline amount is presumed a substantial change; it does not apply to orders under three years old (Wiggs v. Wiggs) |
| Vested payments | A past-due payment cannot be vacated, reduced or modified unless a written motion was filed and notice given before it was due, or promptly after a compelling reason ends (50-13.10(a)) |
| No arrears in some cases | No arrearage accrues while the supporting party is incarcerated, not on work release and without resources, or while the child lives with the supporting party under an agreement (50-13.10(d)) |
| Guidelines and deviations | The court applies presumptive guidelines and may vary on written findings (50-13.4(c)) |
| Nonpaternity | A father can seek relief from an order within one year of learning he is not the father (50-13.13) |
How does child support modification work in North Carolina?
- Know the 15% presumption. See the North Carolina 15% presumption for child support modification.
- File your motion before the payments come due. See how to modify child support in North Carolina.
- Income problems and incarceration. See lowering child support after job loss or incarceration in North Carolina and, for what stays owed, the North Carolina child support arrears calculator.
What does this modification calculator check?
The calculator tests the 15% line and the 3-year condition, and shows the monthly gap and the accrued difference after you file. It cannot decide whether a court will find a substantial change when the presumption does not apply. Payments that came due before your motion are the ones you cannot recover.
Frequently asked questions
How much does child support have to change to be modified in North Carolina?
For an order at least three years old, a difference of 15% or more between the order and the guideline amount is presumed to be a substantial change. Otherwise you must prove one.
Does the North Carolina 15% rule apply to a new order?
No. The presumption applies only to orders at least three years old.
Can North Carolina change support that came due before my motion?
No, unless a written motion was filed and notice given before it was due; each past-due payment is vested when it accrues.
Does a North Carolina jail sentence stop support from building up?
No arrearage accrues while the supporting party is incarcerated, is not on work release and has no resources to make the payment.
Can a North Carolina father get relief from a support order if he is not the father?
He may file within one year of the date he knew or should have known he was not the father.
Official sources
- G.S. 50-13.7: modification of support
- G.S. 50-13.10: past due support vested
- G.S. 50-13.4: action for support of minor child
- Wiggs v. Wiggs, 128 N.C. App. 512: the 15% presumption
- 122 N.C. App. 702: the 15% presumption and guidelines history
- 42 U.S.C. 666(a)(9): no retroactive modification of support already due