Paternity in Ontario: DNA Testing and Declarations of Parentage

Proving the legal bond that triggers both rights and responsibilities

DNA Testing and Legal Documentation

Proving the legal bond that triggers both rights and responsibilities

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Parentage Strategy reviewed by Deepa Tailor, Senior Family Lawyer. Updated January 2026 to reflect the Children’s Law Reform Act and All Families Are Equal Act.

Too Busy to Read? The 30-Second Summary:

The Document:

If you are not on the birth certificate, you may need a “Declaration of Parentage” from the court to assert your rights.

The Test:

The court can order DNA testing. Refusing a test usually results in the court assuming you are the parent.

The Result:

Establishing paternity triggers both Rights (Decision-Making/Access) and Responsibilities (Child Support). You cannot choose one without the other.

Identity & Obligation

Is he the father? Am I the father? These aren’t just emotional questions—they are the foundation of every legal right regarding a child.

Whether you are a mother seeking support, or a father seeking access, the first step is proving the legal bond exists. Without that proof, the system won’t recognize your claim—and the other party can deny everything.

For Fathers: Seeking Access

Source: Children’s Law Reform Act

The Barrier:

If you weren’t married and aren’t on the birth certificate, the school and doctors may not talk to you. The mother can block your access to medical records, report cards, and even prevent you from picking up your child.

Our Strategy:

We file the Application for a Declaration of Parentage to force the system to recognize you. Once the court declares you the legal parent, you have standing to seek a parenting order.

Child Support After Paternity Is Established

The Strategy:

If the biological father denies paternity to avoid paying child support, we file a motion for DNA testing. The court will order him to submit to testing at an accredited lab.

The Result:

Once the test comes back positive, support is retroactive. The court can order support for a period before the order, sometimes back to the child’s birth or to when you first asked for it; the start date is up to the court (Family Law Act, s. 34(1)(f)).

Important Note:

If he refuses the test, the judge may draw whatever inferences the court thinks appropriate (Children’s Law Reform Act, s. 17.2(4)), which can lead to a finding that he is the father without DNA proof.

Court-Ordered vs At-Home DNA Tests

Birth Certificate and Legal Documentation

The Warning:

Do not use a pharmacy DNA kit. The court will reject it because there is no “Chain of Custody”—no proof of who actually gave the sample.

Anyone could have submitted the DNA. The mother could claim you swapped samples. The judge won’t accept it.

Court-Approved DNA Testing Process:

1

Accredited Laboratory

We arrange testing through an accredited lab (such as Viaguard or LifeLabs) where identities are verified with government-issued ID.

2

Chain of Custody

The lab documents who provided each sample, when it was collected, and how it was stored. This creates an unbroken chain of evidence.

3

Court-Admissible Report

The lab issues a report that meets legal standards. The judge can rely on it without requiring the lab technician to testify.

4

Results Timeline

Results typically take 5-10 business days. Accuracy is 99.9%+ for inclusion (positive match) or 100% for exclusion (not the father).

Disputing Parentage

The Scenario:

You signed the birth certificate when the child was born. You believed you were the father. But now, months or years later, you have doubts.

Maybe the relationship ended badly. Maybe someone told you the timeline doesn’t add up. Maybe the child doesn’t look like you.

Can You Challenge It?

Yes, but you must act fast. The law allows you to apply to set aside a Declaration of Parentage or challenge your status on the birth certificate.

However, the longer you wait, the harder it becomes. If you’ve been acting as the child’s parent for years, paying support, spending time together, making decisions, the court may rule that you are the “psychological parent” even if biology says otherwise.

Legal Reality:

Courts prioritize the best interests of the child. If the child has bonded with you and sees you as their parent, the judge may refuse to terminate your obligations, even if DNA proves you’re not the biological father.

This is especially true if:

  • The child is older (typically over 2-3 years)
  • You’ve been paying child support consistently
  • You’ve exercised parenting time regularly
  • The biological father is unknown or uninvolved

Our Approach:

We assess your situation honestly. If you have a strong case (recent discovery, minimal bonding, biological father available), we’ll fight to remove your obligations.

If the court is likely to maintain your status as psychological parent, we’ll help you understand your options and negotiate the best possible outcome.

Paternity FAQs

Common questions about establishing paternity in Ontario

Can I refuse a DNA test?
You can physically refuse, but if the court has granted leave for a test and you refuse, the court may draw such inferences as it thinks appropriate (Children's Law Reform Act, s. 17.2(4)). The court then decides parentage on all of the evidence.
Does a Declaration of Parentage change the Birth Certificate?
Yes. Once the court issues a Declaration of Parentage, the court clerk files a statement about the order with the Registrar General (Children's Law Reform Act, s. 17.4). Any amendment to the birth registration is then made in accordance with the Vital Statistics Act (s. 17.6).
Who pays for the DNA test?
Usually the party requesting the test pays upfront. However, if the test proves the other party was lying or denying paternity in bad faith, the court can order them to reimburse the testing costs. Testing costs depend on the lab and urgency.
How long does the paternity process take?
If both parties cooperate, DNA testing takes 5-10 business days. The court application for a Declaration of Parentage can take several months or longer from filing to final order, depending on court availability and whether the case is contested.
What if the mother refuses to allow DNA testing of the child?
If the mother refuses, you can bring a motion asking the court to order her to bring the child for testing. If she continues to refuse a court order, she can be found in contempt of court, which carries serious consequences including fines or jail time.
Can I get custody or access before paternity is established?
Yes. You do not need a court declaration of parentage first. A parent may apply for a parenting order (Children's Law Reform Act, s. 21(1)), and any other person may apply for decision-making responsibility or a contact order (s. 21(2)-(3)). The court decides based on the child's best interests (s. 24).

Get the Truth. Secure Your Rights.

Whether you’re seeking to establish parentage or challenge it, we provide clear strategy and proven results.

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