The things that hurt a custody case in Utah are, in rough order of damage: any evidence of abuse or domestic violence, interfering with the other parent’s relationship with the child, substance abuse, ignoring court orders, moving away without proper notice, not showing up for your own parent-time, and dragging the child into the conflict. Utah judges decide custody using the best-interest factors in Utah Code 81-9-204, and nearly every one of those mistakes maps directly onto a factor the judge is required to weigh.

Here is what the statute looks at, what parents do that undermines their own case, and how to avoid it.

What Utah judges are required to consider

Utah Code 81-9-204 sets the standard: the best interests of the child, proven by a preponderance of the evidence. Since 2024, three considerations come first, in subsection (3): evidence of domestic violence, physical abuse, or sexual abuse involving the child, a parent, or a household member; intentional exposure of the child to pornography or material harmful to minors; and whether custody or parent-time would endanger the child’s health or safety.

After those, subsection (4) lists factors the court may weigh, including evidence of coercive control (added in May 2026), psychological maltreatment, understanding of the child’s developmental needs, parenting and co-parenting skills, past conduct and moral character, emotional stability, substance abuse, the child’s bond with each parent, primary caretaker history, sibling unity, and the child’s stated wishes.

The co-parenting factor deserves special attention. Subsection (4)(d) asks specifically about each parent’s “ability to appropriately communicate with the other parent,” “ability to encourage the sharing of love and affection,” and “willingness to allow frequent and continuous contact” with the other parent. Utah also presumes joint legal custody is in the child’s best interest under Utah Code 81-9-205, and that presumption is rebutted by evidence of abuse, neglect, or a parent’s inability to cooperate. In short, a parent who cannot co-parent is a parent the statute is designed to see.

Ten mistakes that hurt custody cases in Utah

1. Interfering with the other parent’s time or relationship

Withholding the child, being chronically late for exchanges, scheduling activities over the other parent’s time, or refusing phone calls all go directly to the co-parenting factor. Utah Code 81-9-208 lets the court award attorney fees, costs, and make-up parent-time to the parent whose time was denied. A pattern of interference is the single most common reason a primary caregiver loses that status.

2. Badmouthing the other parent to the child

Telling the child that the other parent is a liar, does not pay support, or broke up the family is psychological maltreatment under factor (4)(b) and a failure to “encourage the sharing of love and affection” under (4)(d). Custody evaluators are trained to detect it in how children talk, and it shows up in text messages parents forget they sent.

3. Social media

Posts about the other parent, photos of partying on your parent-time, or public complaints about the case are all admissible. In Wallace v. Wallace, 2024 UT App 164, the Utah Court of Appeals affirmed a trial court’s order requiring a parent to remove social media posts about the other parent under a non-disparagement clause, and treated the parent’s conduct as supporting a custody modification. Assume the judge will read everything you post.

4. Ignoring temporary orders

Temporary orders entered while the case is pending are court orders. Missing exchanges, not paying temporary support, or changing the child’s school without permission tells the judge you will not follow the final decree either. Contempt is a possible consequence; losing credibility is a certain one.

5. Moving without notice

Under Utah Code 81-9-209, a parent who intends to move 150 miles or more from the other parent must give at least 60 days’ written notice. The statute says a parent who fails to comply “is in contempt of the court’s order.” Even moves that do not trigger the statute can hurt if they disrupt the child’s school or the other parent’s time without discussion.

6. Not exercising your own parent-time

Utah Code 81-9-206(4)(j) lists “a pattern of missing, canceling, or denying scheduled parent-time” as a parent-time factor. If you are asking for more time, the first thing the judge asks is whether you used the time you already had. Cancelling weekends during the case is one of the most damaging things a parent can do.

7. Substance abuse

Factor (4)(g) addresses substance abuse or other dysfunction that impairs parenting. A DUI during the case, a positive drug test, or evidence of drinking during parent-time can result in supervised parent-time under Utah Code 81-9-207. If you have a history, address it proactively with treatment and testing rather than waiting for the other side to raise it.

8. Involving the child in the conflict

Asking the child to carry messages, questioning them about the other parent’s home, showing them court documents, or having them “write a letter to the judge” are all failures to protect the child from conflict, a factor in 81-9-205. Guardians ad litem and evaluators ask children directly whether either parent talks about the case with them.

9. Making false allegations

Abuse allegations are taken seriously and investigated. Allegations that turn out to be fabricated or exaggerated are devastating to the parent who made them, because they demonstrate a willingness to damage the child’s relationship with the other parent to win. Report real concerns through proper channels. Do not manufacture them.

10. Introducing new partners badly

Utah law does not penalize dating. It does weigh moral character (4)(e) and the child’s relationships with stepparents and others in the household (4)(k). Moving a new partner in mid-case, having overnights with the partner during parent-time before the child has adjusted, or a partner with a criminal record all give the other side material.

How custody evaluators and guardians ad litem see these things

In contested cases, the judge often relies on a custody evaluator or a private guardian ad litem. Evaluators are licensed clinicians who interview both parents, the children, and collateral witnesses such as teachers and therapists, and must address the 81-9-204 factors in their report. Since May 2026, Utah Code 81-9-501 through 81-9-504 require evaluators to complete specific training and make their findings advisory only, but judges still give them substantial weight. See Utah Custody Evaluations in 2026: What Changed.

A guardian ad litem, appointed under Utah Code 78A-2-705, must meet with the child personally and report both the child’s wishes and the GAL’s own view of the child’s best interests. Both professionals notice the same things: which parent speaks respectfully about the other, which parent has the school records and the pediatrician’s name, and which parent’s home the child seems relaxed in.

What helps instead

Communicate with the other parent in writing, briefly and civilly, as if the judge will read it, because the judge may. Exercise every minute of your parent-time. Keep a simple log of exchanges, cancellations, and school and medical involvement. Support the child’s relationship with the other parent out loud, in front of the child. Follow every order to the letter and seek modification through the court if an order is not working. And get your own life in order: stable housing, stable work, and, if you have a substance or mental health issue, documented treatment.

Frequently asked questions

What makes a mother lose custody in Utah?

The same things that make a father lose it. Utah Code 81-9-204(7) states there is no preference based on gender. Abuse, interference with the other parent, substance abuse, and instability are the leading causes for either parent.

Can texting or emails be used against me?

Yes. Written communications between parents are routinely admitted. Co-parenting apps that log messages are common in Utah cases for exactly this reason.

Does a criminal record hurt a custody case?

It depends on the offense and how recent it is. Domestic violence and offenses involving children are weighed heavily under 81-9-204(3). An old, unrelated conviction with a clean record since carries little weight.

What if the other parent is doing these things?

Document it, do not retaliate, and bring it to your attorney. Interference and disparagement by the other parent are grounds for enforcement under 81-9-208 and, if persistent, for modification.

Talk to a Utah custody attorney before you make a mistake you cannot undo

Most damage in custody cases is done early, before the parent has a lawyer explaining what the judge will see. If you are heading into a custody dispute or are already in one, CoilLaw represents parents across Utah and can tell you where your case is strong and where it is exposed. Contact us to schedule a consultation.