What Counts as a Substantial Change in Circumstances for Child Support in Utah
In Utah, child support is adjusted on a substantial change in circumstances if the difference from the guidelines is 15% or more and not temporary, or by motion at 10% when the order is at least three years old.
What is a substantial change in circumstances for child support in Utah?
A parent, legal guardian or the Office of Recovery Services may at any time petition the court to adjust the order if there has been a substantial change in circumstances. The statute says a substantial change may include material changes in custody, in the relative wealth or assets of the parties, of 30% or more in a parent’s income, in a parent’s employment potential and ability to earn, in the child’s medical needs, or in either parent’s legal responsibility to support others (Utah Code 81-6-212(3)).
What is the Utah 15% test?
After finding a substantial change, the court determines whether it produces a difference of 15% or more between the ordered amount and the guideline amount, and adjusts the order to the guidelines if the difference is 15% or more and not temporary (81-6-212(4)). The Utah child support modification calculator tests it.
| Existing monthly order | 10% up | 10% down | 15% up | 15% down |
|---|---|---|---|---|
| $200 | $220 | $180 | $230 | $170 |
| $500 | $550 | $450 | $575 | $425 |
| $800 | $880 | $720 | $920 | $680 |
| $1,500 | $1,650 | $1,350 | $1,725 | $1,275 |
With an $800 order, $1,000 is 25% higher and passes both lines; $880 is 10%, enough for the three-year motion but not for a petition.
What is the Utah three-year motion?
If the order has not been issued or modified within the previous three years, a parent, guardian or the office may move to adjust it. The court compares the ordered amount with the guideline amount and adjusts it if the difference is 10% or more, is not temporary, and the new order does not deviate from the guidelines; a substantial change does not have to be shown (81-6-212(5)).
Do new Utah support tables count?
No. A change in the child support tables is not a substantial change in circumstances (81-6-212(3)(b)). A higher table does not by itself justify a petition.
What is a temporary change in Utah?
The statute says the difference must not be of a temporary nature (81-6-212(4), (5)). A short layoff or a one-time bonus may not qualify; bring records showing how long the change will last.
From what date can the order change?
A support payment may be modified only for a period when a modification is pending, from the date of service of the pleading on the other party, and the modification takes effect the month following service; the court then enters a judgment for the difference from service until the final order (81-7-102(5)). Every month before the month after service is lost:
| Monthly difference | Lost after 6 months | Lost after 12 months |
|---|---|---|
| $100 a month | $600 | $1,200 |
| $200 a month | $1,200 | $2,400 |
| $400 a month | $2,400 | $4,800 |
Federal law also bars retroactive modification of support already due (42 U.S.C. 666(a)(9)).
What does the court consider when it decides?
It acts taking into account the best interests of the child, first deciding whether a substantial change occurred and then whether the difference is 15% or more (81-6-212(4)).
What happens next?
Read how to modify child support in Utah for the filing steps, and check what stays owed with the Utah arrears calculator.
Frequently asked questions
What is a substantial change in Utah child support?
A material change in custody, wealth, income of 30% or more, ability to earn, the child's medical needs or legal responsibilities for others.
Is the Utah difference test 10% or 15%?
15% on a petition for a substantial change; 10% on a motion when the order has not been issued or modified in three years.
Can a temporary change modify Utah child support?
No. The difference must not be of a temporary nature.
Do Utah support table changes modify my order?
No. A change in the tables is not a substantial change.
Can Utah modify support due before service?
No. Only from the date of service, effective the month after.
Official sources
- Utah Code 81-6-212: modification of child support order
- Utah Code 81-7-102: payments as judgments; modification timing
- Utah Courts: modifying child support
- 42 U.S.C. 666(a)(9): no retroactive modification of support already due
- 45 CFR 302.56: federal guideline requirements
A local family law attorney can review your situation — many offer a free consultation.
This is general information, not legal advice. It is based on the cited Utah statutes, rules and court opinions, and every case turns on its own facts. Confirm how the law applies to your situation with a licensed Utah attorney.