Paternity Tests & Terminating Child Support in Ontario
Discovering you are not the biological father is devastating. Learn the legal steps to challenge parentage and whether a negative DNA test actually ends your financial obligations.
Legal Review: This parentage guide was reviewed by Deepa Tailor, Senior Family Lawyer, to ensure compliance with the Children's Law Reform Act regarding blood tests and declarations of non-parentage (2026).
Does a Negative DNA Test Stop Support?
Not automatically. While a negative DNA test proves you are not the biological father, you may still be a 'parent' in the eyes of the law. If you lived with the child and treated them as your own for a significant time ('Settled Intention'), the court may find you stand in Loco Parentis. In these cases, a judge can order you to continue paying support even after a negative paternity test, to protect the child's emotional and financial stability.
Biology vs. Relationship
The Newborn (Early Discovery)
If the child is an infant and you challenge paternity immediately, a negative test usually ends all obligations. You haven't formed a 'parental relationship' yet.
The Older Child (Late Discovery)
If you raised the child for 10 years believing they were yours, courts often rule that the relationship outweighs the biology. Support may continue.
The Birth Certificate
Signing the birth certificate creates a presumption of parentage. You need a Court Order (Declaration of Non-Parentage) to overturn this.
Refusal to Test
If the mother refuses a DNA test, we can file a motion for 'Leave' to obtain one. If she still refuses, the court can assume she is hiding the truth.
Why You Might Still Pay
The law prioritizes the child's best interests over the truth of biology.
Biological Parent
Based on DNA. Liability is automatic and usually absolute. You pay the full Table Amount.
Psychological Parent (Loco Parentis)
Based on conduct. Did you let the child call you Dad? Did you pay for their school? If yes, you are a 'parent' under the Family Law Act. However, your support obligation might be reduced to a 'secondary' level.
How to Challenge Paternity & End Support
The Request
We send a formal request for a DNA test. DO NOT use a pharmacy 'home kit.' It must be a court-approved lab to be admissible evidence.
Motion for Leave
If refused, we file a motion under Section 10 of the Children's Law Reform Act asking the court to order the test.
Declaration of Non-Parentage
If the test is negative, we apply for a court order formally declaring you are not the parent.
Motion to Change Support
We take that Declaration and file a Motion to Change (Form 15) to terminate the support order and notify the FRO.
Paternity FAQs
Related Resources
Step-Parent Support Obligations
Understanding when step-parents become legally responsible for child support.
Motion to Change Support (Form 15)
How to formally modify or terminate a child support order.
Child Support Arrears
Managing accumulated child support debt and enforcement actions.
Deepa Tailor
Senior Family Lawyer
Deepa Tailor is the founder of Tailor Law. She handles sensitive paternity disputes, helping clients navigate the intersection of biological truth and legal parental obligations.
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