Child Support for Adult Children in Ontario

Does Child Support Automatically End at 18?

Generally, no. It is a common assumption that child support simply stops the moment a child reaches the age of majority (18 in Ontario), but that is not how the federal Divorce Act is written. Instead, the Act defines which children remain eligible for support using a broader test that can, in the right circumstances, continue to apply well past a child's 18th birthday. For a shorter look at this exact question, see our companion article on whether child support ends at 18, and our overview of child support after separation generally.

This does not mean support continues indefinitely, or that every adult child qualifies. It means there is no single fixed cutoff — the answer depends on the child's actual circumstances, assessed under the definition described below.

This question comes up constantly for separated and divorcing parents, often because a separation agreement or court order was drafted years earlier without anticipating that a child might still be in school, ill, or otherwise dependent well into their twenties. Many parents are surprised to learn that "18" does not appear anywhere in the Divorce Act as a support cutoff — the Act instead asks a functional question about dependency, not a purely chronological one.

The Divorce Act Definition of "Child of the Marriage"

Support obligations under the Divorce Act are tied to a defined term: "child of the marriage." Broadly, this generally includes a child of two spouses or former spouses who is either still under the age of majority and has not withdrawn from their parents' charge, or who is at or over the age of majority and remains under that charge but is unable — because of illness, disability, or another recognized cause — to withdraw from it or to obtain the necessaries of life on their own.

The key phrase is "or other cause." The Divorce Act does not list every situation that can keep an adult child within this definition, and courts have generally read that phrase broadly rather than narrowly, which is part of why pursuing further education is commonly treated as qualifying. Age of majority itself is generally set by the law of the province where the child habitually lives, which is 18 in Ontario.

This is a general summary of a legal test, not a checklist. Whether it applies to your family depends on the specific facts, and confirming the current wording directly is always worthwhile — see Sources & Further Reading below.

It is also worth noting that "child of the marriage" is a Divorce Act concept, tied to parents who married and are divorcing or divorced. Parents who were never married, or who are married but not pursuing a divorce, are instead generally governed by Ontario's own support rules, discussed further in When Support for an Adult Child Might End below.

Full-Time Students and Post-Secondary Education

The single most commonly discussed example of an "other cause" is a child's attendance at full-time post-secondary education — college, university, or a similar program. Courts have generally been willing to treat a child pursuing full-time studies as still under a parent's charge and unable to fully support themselves, particularly where the child is pursuing further education in a manner consistent with the family's expectations before the parents separated.

This is not automatic or unlimited. Courts generally look at the whole picture — things such as whether the program is genuinely full-time, whether the child is making reasonable progress, the child's own plans and resources, and how long the pursuit of education can reasonably continue to justify ongoing support. A child who is not enrolled, who is studying only part-time, or who has already completed a first program is not automatically covered by this reasoning.

A gap year, a change in program, or a slower-than-expected pace of study does not automatically end an adult child's entitlement, but it can affect how a court views the situation, including any later retroactive child support claim if support was not adjusted at the time. Communication between parents, and between parents and the child, about education plans is often what determines whether an arrangement continues smoothly or ends up disputed.

Illness, Disability, or Other Circumstances

The Divorce Act's definition also expressly recognizes illness or disability as a reason a child at or over the age of majority may remain unable to withdraw from parental charge. Where a child's illness or disability genuinely prevents them from supporting themselves or living independently, support can continue for as long as that dependency exists, without being tied to a school program at all.

Because "or other cause" is not limited to a fixed list, other circumstances can also be relevant depending on the facts. These situations are generally more individualized than the post-secondary scenario above, so professional guidance is often especially useful here.

Does the Standard Table Amount Still Apply?

Where a child remains a "child of the marriage" despite being at or over the age of majority, the Federal Child Support Guidelines generally direct a court to start from the same table-based approach used for younger children — the same basic amount linked to the paying parent's income, the number of children, and the province of residence. Read more about how child support is generally calculated and child support calculations, or try our child support calculator to see how the standard table amount is generally estimated.

However, the Guidelines also give a court discretion to depart from that table approach for an adult child if the court considers the standard approach inappropriate in the circumstances. Where a court takes that different approach, it can instead set an amount it considers appropriate, having regard to the child's own condition, means, needs, and other circumstances, together with each parent's financial ability to contribute. This is commonly discussed in situations such as an adult child living away from home at school, where the costs and resources involved can look quite different from a younger child living with a parent full-time.

In practice, this means there is no single formula that automatically applies to every adult child — some cases proceed on the standard table amount, and others do not, depending on the court's assessment of what is appropriate. Because this is a genuine choice between two different approaches, rather than a mechanical calculation, it is one of the more commonly negotiated or litigated aspects of adult-child support, and one where professional guidance can be particularly useful.

Does the Child's Own Income Matter?

It can, particularly once a court has decided that the standard table approach is not appropriate. Where a court considers the adult child's own condition, means, and needs, a child's own income, savings, government student loans or grants, and reasonable ability to contribute through part-time work are commonly part of that broader assessment.

This does not mean any income at all disqualifies an adult child from support, or that support is reduced dollar-for-dollar against everything a child earns. Courts generally look at the child's overall circumstances and reasonable expectations — for example, typical part-time earnings during a school term are treated differently than a full-time salary from a completed career. Because this analysis is fact-specific, outcomes vary considerably between families.

Some parents and courts also consider whether it is reasonable to expect the adult child themselves to contribute toward costs like tuition, particularly where the child has access to summer or part-time earnings, scholarships, or student loans. There is no set formula for how much a child should be expected to contribute, and approaches vary — which is another reason this issue is often addressed through negotiation or a court application rather than assumed.

When Support for an Adult Child Might End

Because there is no fixed age cutoff, support for an adult child generally ends when the child is no longer under a parent's charge and can reasonably be expected to support themselves — for example, once they finish a first program of study, become employed, get married, or otherwise become independent in a way that takes them outside the Divorce Act's definition. Some commonly discussed circumstances include:

• Completing a first post-secondary program or degree
• Voluntarily withdrawing from school without a recognized reason to remain dependent
• Obtaining stable full-time employment
• No longer being under a parent's charge in a practical sense
• A recovery from illness or disability that removes the basis for continued dependency

None of these automatically ends support the moment they occur — a parent who believes support should stop or change generally still needs to address that through an agreement or the court process, rather than simply stopping payment unilaterally. Read more about changing a support amount.

For parents who were never married, or who are married but not pursuing a divorce, Ontario has its own Family Law Act, which contains a related but not identical obligation, including provisions relevant to a child in a full-time program of education. The general themes discussed on this page — no fixed cutoff, and a focus on whether the child remains genuinely dependent — tend to carry across both frameworks, but the exact wording differs, so confirm which law applies to your family before assuming the details are identical.

How This Interacts With Special Expenses

Adult-child support questions frequently overlap with special or extraordinary expenses, particularly post-secondary tuition and related costs. Tuition, books, and similar education costs are commonly addressed as a special expense shared between parents, on top of whatever basic support amount applies to the child under the analysis above. Read more about special and extraordinary expenses, including how these costs are generally shared and adjusted for any related subsidy or benefit.

Because both the basic amount and any special expenses can be affected by an adult child's own resources, these two issues are often worked out together — whether through negotiation, updating an existing agreement, or a court process — rather than in isolation.

Frequently Asked Questions