How to Establish Paternity If the Father Is in Another State

To establish paternity when the father lives in another state, start with your local child support enforcement agency, which will either help you obtain a voluntary acknowledgment or file an interstate case under the Uniform Interstate Family Support Act (UIFSA). You do not need to travel to his state, and in most situations you do not need to hire an attorney there. Federal law requires every state to provide these services and to honor paternity determinations made in other states.

Start With a Voluntary Acknowledgment If He’ll Sign

If the father accepts that he is the biological parent, court is unnecessary. Every state must offer a simple voluntary acknowledgment of paternity, available at the hospital after birth or later through the state’s vital records office, and both parents must be told the legal consequences before signing.¹

The key point for interstate situations: every state must give full faith and credit to a voluntary acknowledgment signed in any other state.² If the father signs the form in his home state using that state’s procedures, your state must treat it as binding. Paternity is established without a hearing, without genetic testing, and without any jurisdictional argument.

Either parent can rescind within 60 days of signing. After that, the acknowledgment can only be challenged in court on grounds of fraud, duress, or a material mistake of fact, and it otherwise carries the same weight as a court order.¹

Open a Case With Your State’s Child Support Agency

The most useful step most people miss is applying with their state’s Title IV-D child support agency. Federal law requires every state to provide paternity establishment services to anyone who applies, not just people receiving public assistance, and caps the application fee at $25.³

When the father lives in another state, your agency acts as the “initiating” agency. It prepares the paperwork, works to locate him, and transmits the case to the child support agency in his state. That “responding” agency then processes the case as if it were local, files in court, and provides an attorney to represent the agency in the proceedings.⁴ You will not need to appear in the other state’s court or retain your own lawyer there.

The alternative is filing a private action and managing the interstate logistics yourself. That is more expensive and more complicated, and there is rarely a reason to do it before trying the agency route.

How a Court Reaches an Out-of-State Father

If the father won’t cooperate and a court case is needed, the first question is whether a court in your state has personal jurisdiction over him. UIFSA gives your state’s court authority over a nonresident father in a paternity case if any of the following is true:

He lived with the child in your state, even briefly.
He lived in your state and provided prenatal expenses or support for the child.
The child lives in your state because of his acts or directives, such as telling the mother to move there.
He had sexual intercourse in your state and the child may have been conceived from that encounter.
He was personally served with legal papers while physically present in your state.
He consented to jurisdiction by filing a response or appearing in the case.

These are the “long-arm” bases under UIFSA. If none of them fits, the case does not stop. UIFSA also provides a two-state process: your local court or child support agency serves as the “initiating tribunal” and forwards your petition to the appropriate court in the father’s state, which becomes the “responding tribunal.” The responding court files the petition, tells you when and where it was filed, and then handles the case, including determining parentage, setting support, and enforcing the order. The responding agency must process the case on the same terms it would use for its own residents.³

In practice, you file locally and the system moves the case. Hearings may happen by phone or video rather than in person.

Serving the Father in Another State

The father must receive formal notice before a court can make a binding paternity determination. Due process requires actual notice and a chance to respond. The usual approach is a process server or the sheriff’s office in his county, with sheriff service fees typically between $30 and $90. Some jurisdictions also allow service by certified mail with return receipt requested. If you are working through a Title IV-D agency, it can arrange service through its counterpart in his state.

If his address is unknown, courts may allow service by publication as a last resort, but only after you demonstrate a diligent search: contacting relatives, checking social media and online directories, following up with employers, trying last-known addresses, and asking the post office about forwarding. You file an affidavit listing every step. If the court agrees, the summons is published in a local newspaper for several consecutive weeks. This form of service is authorized but weaker in practice, because the father may never see it and some courts hesitate to issue broad orders based on publication alone.

If the father lives outside the country, the Hague Service Convention may govern how documents must be delivered, which involves formal transmission to a Central Authority in the receiving country and typically translations.⁵ International service takes considerably longer than domestic service.

Genetic Testing When Parents Live in Different States

Federal law requires states to order genetic testing in contested paternity cases when either party requests it and provides a sworn statement supporting their position.¹ Testing is a cheek swab from the child, the mother, and the alleged father.

When parents live in different states, the court’s order typically identifies approved testing facilities in each location and sets collection deadlines. For results to hold up in court, the lab should be accredited by the AABB (formerly the American Association of Blood Banks). AABB accreditation is technically voluntary, but many states require it for admissibility and most court systems recognize AABB-accredited facilities.⁶

In IV-D cases the state agency pays for the test and can recover the cost from the father if paternity is confirmed.¹ If you are filing privately, expect roughly $500 upfront for a three-party legal test, though the court can order the father to reimburse you. Results at 99% probability of paternity or higher are treated as conclusive in virtually every jurisdiction. If the father refuses to submit to court-ordered testing, most jurisdictions treat that refusal as an adverse inference and can presume paternity from the available evidence; continued refusal may lead to contempt sanctions.

What the Order Gives the Child

Once the court reviews the test results and other evidence, it enters an order establishing paternity. That order creates a permanent legal relationship, with real consequences:

Child support can be set immediately using the father’s income and the state’s guidelines.
Either parent can petition for custody or visitation; the father gains standing to seek parenting time.
The child becomes a legal heir.
The child can qualify for Social Security benefits through the father, including survivors benefits and disability-related benefits.⁷
The child gains access to the father’s family medical history.

The father’s name can be added to the birth certificate once paternity is established by a voluntary acknowledgment or a court order.¹

Enforcing the Order Across State Lines

Getting the order matters less than making it stick. UIFSA lets a paternity and support order from one state be registered in the father’s state and enforced there as if it were local, and your child support agency handles the registration.

Federal law gives states a broad set of enforcement tools when a parent falls behind:¹

Income withholding directly from the father’s paycheck, which is the default in most IV-D cases.
Suspension or restriction of driver’s, professional, and recreational licenses.
Interception of state and federal tax refunds.
Automatic liens against real and personal property, which states must honor across state lines.
Reporting of delinquent support to consumer credit agencies.
Referral to the federal Passport Denial Program once arrears reach $2,500, blocking passport issuance or renewal.⁸

These tools work across state lines because the responding state’s agency must enforce out-of-state orders. If enforcement stalls, contact your local agency to confirm your case is active and that the responding state has current information about the father’s employer and address.

Deadlines and How Long This Takes

Federal law allows paternity to be established at any time from birth until the child turns 18.¹ Filing sooner protects the child. Support obligations typically begin from the date of the petition rather than from birth, so every month of delay is support you cannot recover later. Benefits like Social Security coverage also depend on the legal relationship being in place before the triggering event.

Interstate cases move more slowly than local ones. An uncontested case usually takes three to six months once you factor in locating the father, service, coordinating testing across two states, and hearings. Contested cases, or cases where the father is hard to find, can stretch past a year. Starting through your Title IV-D agency early keeps the case moving and closes gaps in support.

1
Office of the Law Revision Counsel. 42 USC 666 – Requirement of Statutorily Prescribed Procedures
2
Administration for Children and Families (ACF). IM-95-03 – Full Faith and Credit for Child Support Orders Act
3
Office of the Law Revision Counsel. 42 USC 654 – State Plan for Child and Spousal Support
4
Administration for Children and Families (ACF). Action Transmittal – Interstate Child Support Policy
5
Hague Conference on Private International Law. Convention on the Service Abroad of Judicial and Extrajudicial Documents in Civil or Commercial Matters
6
AABB. DNA Relationship Testing FAQs
7
Social Security Administration. Benefits for Children
8
Administration for Children and Families (ACF). Passport Denial Program 101