Do Both Parents Have to Consent to a DNA Test?

Do both parents have to consent to a DNA test? For a legal, court-admissible paternity test on a minor, the default answer is yes: most accredited labs expect consent from both legal parents or a court order before they will swab a child. But that default has real exceptions. A parent with sole legal custody can usually authorize testing alone. Informational home kits operate under looser rules. And when one parent refuses, the other can ask a court to order the test anyway — a route federal law requires every state to provide.

Why Dual Consent Is the Default

When two parents share legal custody, both generally need to agree before a child undergoes a legal DNA test. Legal custody is shared decision-making authority over the child’s medical and legal matters, and a paternity test touches both. Neither parent, acting alone, should be able to initiate a process that can reshape the child’s legal identity, support obligations, and family relationships.

Major testing laboratories build this into their intake rules. They require consent from a legal guardian or a court order before collecting samples from a minor. The policy protects against one parent using a test as leverage in a custody fight, or arranging testing behind the other parent’s back. If one parent objects and the other pushes a legal test through anyway, the results can be challenged or excluded in court. So for anything that will carry legal weight, the practical rule is simple: get both parents to sign on, or get a judge to sign an order.

What Happens When the Other Parent Refuses

Refusal doesn’t end the matter. Under 42 U.S.C. § 666, every state must have procedures requiring all parties in a contested paternity case to submit to genetic testing when any party files a sworn statement either claiming or denying paternity, supported by facts showing a reasonable possibility of sexual contact (or its absence) between the parties.¹ Neither a mother nor an alleged father can simply refuse once the court is involved.

Courts typically order DNA testing in paternity actions, child support enforcement cases, and custody or visitation disputes where biological parentage is in question. The order converts what would otherwise require mutual agreement into a legal obligation. The state pays for the initial test in many cases and can recoup the cost from the father if paternity is established.¹

How to Ask the Court for an Order

Either parent can petition the court, and so can an alleged father who isn’t on the birth certificate. The petitioner files a sworn statement explaining why testing is warranted. Courts generally grant these requests because the law favors a factual determination of parentage. Filing fees for a paternity petition vary by jurisdiction, ranging from nothing to several hundred dollars, and fee waivers are available in many courts for people who can’t afford them.

When a Court May Say No

Courts don’t rubber-stamp every request. Under the Uniform Parentage Act, adopted in various forms by numerous states, a court can refuse to order genetic testing if it finds that disproving an existing father-child relationship would be inequitable.² Judges weigh how long the presumed father has acted as a parent, the child’s age, the nature of the relationship, and the potential harm to the child. A man who has raised a child for a decade and only now wants to disprove paternity may find that the court values the child’s stability over biological certainty.

When One Parent’s Consent Is Enough

Dual consent is the default, not a universal rule. Several situations allow a single parent, or no parent at all, to authorize testing.

Sole Legal Custody

A parent who holds sole legal custody has exclusive authority over the child’s medical and legal decisions. That authority generally extends to consenting to a DNA test without the other parent’s agreement. The key word is “legal.” Physical custody alone doesn’t grant this power. The custody order itself needs to assign sole legal decision-making to one parent.

Informational Home Tests

Home DNA kits sold online and in pharmacies work differently from court-admissible tests. They’re designed for personal knowledge, confirming or ruling out a biological relationship, and the results don’t carry legal weight. Because no court proceeding depends on the outcome, the consent rules are looser. A parent with legal standing, such as someone named on the birth certificate or with custody, can often collect samples from a child for a home test. Kits typically run $130 to $200.

The trade-off matters. Home test results generally aren’t admissible in court. If you need results that will hold up in a paternity action, a child support case, or a custody dispute, an informational test won’t get you there, no matter who consented.

Adult Children

Once a child turns 18, they can consent to their own DNA test. No parental permission is required. Major testing companies also require buyers to be at least 18.³ An adult child seeking to establish or disprove paternity has full autonomy over that decision.

What Refusing a Court-Ordered Test Costs

Refusing a court-ordered DNA test doesn’t make the case disappear. It makes it worse for the person refusing.

Contempt

A court order to submit to genetic testing is binding. Defying it can result in a contempt finding, with sanctions ranging from fines to jail time depending on the jurisdiction. Courts have broad discretion, and repeated refusal escalates the consequences.

Adverse Inference

Often more consequential: the court can simply assume the test would have confirmed what the other party claims. Under the Uniform Parentage Act, if a party declines court-ordered genetic testing, the court may adjudicate that person as the child’s parent even without a genetic relationship on the record.⁴ Refusing a DNA test can lead to a finding of paternity and a child support order without a single swab being collected.

Even outside a formal order, refusing a requested test during ongoing litigation signals something to the judge. Courts routinely treat refusal as evidence weighing against the refusing party. A father who denies paternity but won’t test undermines his own position. A mother who blocks testing may find the court drawing its own conclusions about why.

Why “Legal” Testing Has Stricter Consent Rules

The reason labs ask for both parents’ consent on a legal test, but not on a home kit, comes down to chain of custody — the documented trail proving that the sample actually came from the person it’s supposed to represent.

A court-admissible paternity test requires:

Supervised collection by a trained professional, not the test subjects themselves.
Identity verification. Every participant presents government-issued photo ID. For minors, a birth certificate or similar documentation is required.
Tamper-proof handling. Samples are sealed, labeled, and tracked from collection through analysis. Photographs and fingerprints are often taken at collection.
Analysis by an accredited laboratory. Federal law requires results to come from a lab approved by an accreditation body designated by the Secretary of Health and Human Services, which in practice means AABB accreditation.¹

A legal paternity test typically runs $300 to $500. The gap between a home kit and a legal test is the supervised collection, the identity verification, and the chain-of-custody documentation that courts demand. Consent from both legal parents is part of that same evidentiary chain. Skip it on a legal test and the results risk being thrown out.

A Note on the Marital Presumption

If the child was born during a marriage, the mother’s husband is presumed to be the biological father. The presumption also covers children born within 300 days after a marriage ends through death, divorce, or annulment. Under the Uniform Parentage Act, that presumption can be disproved only through admissible genetic testing that either excludes the presumed father or identifies another man as the biological father.² As noted above, a court can still refuse to order testing if the presumed father has acted as the child’s parent for years and disrupting the relationship would harm the child. Biology doesn’t automatically override an established family bond.

Don’t Wait Too Long to Act

Most states allow a paternity action to be filed at any point before the child turns 18, but deadlines vary, and some states impose shorter windows for challenging an existing paternity determination. If you signed a voluntary acknowledgment of paternity, you have 60 days (or until a court proceeding involving the child, whichever comes first) to rescind. After that, overturning it requires proving fraud, duress, or material mistake of fact.¹ If paternity is something you need to establish or contest, the legal options available today may not be available next year, and witness testimony about the relationship only gets harder to gather with time.

1
Office of the Law Revision Counsel. 42 USC 666 – Requirement of Statutorily Prescribed Procedures to Improve Effectiveness of Child Support Enforcement
2
Administration for Children and Families. Uniform Parentage Act (2000)
3
Ancestry. Ancestry Terms and Conditions
4
Uniform Law Commission. Uniform Parentage Act (2017)