Child Support After Sperm Donation or Assisted Reproduction in Ontario

Many families in Ontario are formed with a sperm donor, an egg donor, an embryo or a surrogate. If you are a donor, you may worry that helping someone have a child could leave you owing child support years later. If you are an intended parent or a birth parent, you may wonder who the law treats as the child's other parent.

The short answer is that support follows parentage. Before anyone asks who pays, the first question is who is legally a parent. This article explains the basic Ontario rules on that question and what to do before and after conception to avoid disputes.

Parentage comes before support

Whether someone has a support duty depends on how the law treats them in relation to the child, so parentage is the first question to sort out. That is why most disputes involving donors and assisted reproduction are really disputes about parentage.

Ontario's Children's Law Reform Act deals with this directly. A person who provides reproductive material, such as sperm or an egg, or an embryo for use in assisted reproduction is not, by that fact, a parent of the child. The key words are "by that fact". Being the genetic source does not automatically create parental status in an assisted reproduction setting. There are exceptions, including the surrogacy rules and court declarations, so the facts of your situation still matter.

Who is treated as a parent in common situations

The table below summarizes the three rules most people ask about. It is a general guide, not a substitute for advice on your own documents.

Notice how much depends on paperwork and timing. A written agreement made before conception can change the result for a spouse, and a surrogacy arrangement depends on both a pre-conception agreement and a consent given after the child is seven days old.

Once someone is a parent, how support is set

If a person is a legal parent, child support under the tables is generally based on the paying parent's income. The federal child support tables were updated, and Ontario.ca says the new amounts apply to all Ontario child support matters starting October 1, 2025. The tables run only to $150,000 of income. If a paying spouse earns more, the court may apply the table amount for the first $150,000 and an amount it considers appropriate on the rest.

Support can also include a share of special or extraordinary expenses, such as child care expenses or health-related costs above what insurance covers, if a parent asks the court for that. Where each parent has the child at least 40% of the time over a year, the court must look at the table amounts for each parent, the increased costs of shared parenting and each household's circumstances rather than simply applying one table.

Only a court can change the amount of support once it is set, and the Family Responsibility Office says it cannot change the amount a payor pays. That makes it important to get parentage and the starting arrangement right.

Why written agreements matter

Because the statute turns on things like a written agreement before conception and written consent after a surrogate birth, informal understandings carry real risk. A text message saying "you will never have any responsibility" is not the same as a properly prepared agreement, and whether any particular document will hold up depends on its content and timing.

• Donors: ask whether the arrangement is through a clinic or private, and have the terms written down and reviewed before conception.
• Birth parents with a spouse: if you and your spouse want a different result from the default rule, that must be in a written agreement made before conception.
• Intended parents using a surrogate: the agreement must exist before conception, and written consent comes only after the child is seven days old.
• Anyone whose situation does not fit these patterns, such as a known donor who later acts as a parent, should get advice, since a court can make declarations about parentage.

What to do next

Whether you are planning a family or already facing a support claim, start with documents and timing.

• Gather any clinic records, donor agreements, surrogacy agreements and consent forms.
• Note dates carefully: when the agreement was signed, when conception occurred and when the child was born.
• Write down who has been caring for the child and how parenting has worked in practice.
• Do not ignore a support application or a letter from the Family Responsibility Office. Respond and get legal advice promptly.
• If you are still planning, speak with a family lawyer before conception, since the rules reward preparation.

Frequently asked questions