What Is Child Support?

Child support is a regular payment made by a parent to help cover the cost of raising a child, generally paid by a parent the child does not live with most of the time, or from a higher-income to a lower-income parent in shared-parenting situations. In Canadian family law, support is treated as belonging to the child, not the parent who receives it — a point that shapes many of the rules below.

Support is generally worked out using a "Guidelines" framework rather than left entirely to negotiation, so similarly situated families end up with broadly similar outcomes. The framework has two closely related versions, described in Which Guidelines Apply.

Who Has to Pay Child Support?

A parent generally has a legal obligation to help support their child financially, regardless of whether the parents were ever married, are separating, or are already divorced, and regardless of how often the parent currently sees the child. This obligation applies to biological and adoptive parents, and in some cases to a person who has stood "in the place of a parent," such as a step-parent who has treated the child as their own.

Support is typically paid by the parent the child spends less time with, though the calculation looks different where parenting time is shared close to equally — see Shared Parenting and Child Support.

Which Guidelines Apply: Federal vs. Ontario

Child support amounts across Canada are generally calculated using the Federal Child Support Guidelines, a regulation made under the federal Divorce Act. These Guidelines, and the tables attached to them, apply when parents are married and are pursuing a divorce.

For parents who are not divorcing — because they were never married, or are married but not seeking a divorce — Ontario has its own Child Support Guidelines, a regulation made under the Family Law Act. Ontario's Guidelines largely mirror the federal version, so the general concepts here, such as the table amount and special expenses, apply either way. Which Guidelines technically govern your situation can still matter procedurally, so confirm which applies to you. Read more about divorce in Ontario.

How the Basic ("Table") Amount Is Generally Calculated

Both the federal and Ontario Guidelines set out tables that generate a basic monthly support amount, generally based on three things: the paying parent's income, the number of children being supported, and the province where the paying parent lives. The tables are built from a broader formula that accounts for typical tax treatment of income, so that the resulting amount reflects a parent's general ability to pay.

Because table amounts and income brackets are updated periodically, this page does not state specific dollar figures. For an actual monthly amount, use the official table look-up tools linked in Sources & Further Reading below, try this site's own child support calculator for a general estimate, or speak with a qualified professional.

What Counts as "Income"

Income generally starts from a broad measure similar to total income reported for tax purposes, and can include employment income, bonuses, and overtime. Self-employment income and income from a corporation a parent controls can involve additional adjustments, which is a common source of disagreement between parents.

Special and Extraordinary Expenses (Section 7)

On top of the table amount, parents may also share certain additional costs, often called "special or extraordinary expenses" because they are addressed in section 7 of the Guidelines. These are expenses generally necessary for the child, reasonable given the family's circumstances, and consistent with pre-separation spending.

Commonly discussed categories include:

  • Childcare needed so a parent can work or study
  • Health-related expenses not covered by insurance
  • Extracurricular activities that are extraordinary for the family
  • Post-secondary tuition and related education costs

Unlike the table amount, section 7 expenses are generally shared roughly in proportion to each parent's income, rather than paid entirely by one parent, and are often adjusted for any related tax benefit or subsidy.

Shared Parenting and Child Support

Section 9 of the Guidelines addresses situations often described as "shared parenting," generally referring to arrangements where a child spends a significant portion of time — commonly discussed as at least 40% of the time over the course of a year — with each parent. Meeting this general threshold does not automatically produce a fixed formula; instead, courts retain discretion to consider the table amounts each parent would otherwise owe, the increased costs of running two homes for the child, and the overall means, needs, and circumstances of each parent and the child.

Because these calculations are more fact-specific than a table lookup, and parenting-time percentages are sometimes disputed, professional guidance is often especially useful here. Read more about shared parenting and child support and parenting time.

Child Support for Adult Children

A common misunderstanding is that child support automatically ends on a child's 18th birthday. Under the Divorce Act, support can continue for a "child of the marriage" past the age of majority, most commonly where the child remains enrolled in full-time school or is otherwise unable to withdraw from parental charge, for example due to illness or disability. Ontario's own Guidelines contain broadly similar concepts.

Whether a particular adult child still qualifies, and how much support is appropriate once a young adult has some independent income, are fact-specific questions courts approach flexibly. Read more about child support for adult children.

Retroactive Child Support

"Retroactive child support" refers to support found to have been owed for a period in the past, rather than only going forward from a court order or agreement. Canadian courts have confirmed that retroactive awards are a recognized part of the framework, not a rare exception, reflecting that support is the child's right and generally cannot simply be waived by a parent.

How far back an award can reach depends on the circumstances, including when the recipient raised the issue and whether the paying parent engaged in blameworthy conduct, such as concealing an income increase. Read more about retroactive child support.

Child Support and Separation Agreements

Parents can agree on child support terms themselves rather than going to court, often as part of a broader separation agreement. Because support belongs to the child, an agreement providing significantly less than the Guidelines would suggest can still be reviewed and adjusted by a court later if not in the child's interests.

A support agreement is also generally easier to enforce if filed with the court, which is part of what lets the Family Responsibility Office enforce it directly — see Enforcing Child Support.

Child Support and Divorce

Child support is not automatically part of a divorce, but it is one of the issues, sometimes called "corollary relief," that is commonly addressed either in the same application as the divorce itself or separately through an agreement. A judge finalizing a divorce will generally want to be satisfied that reasonable arrangements exist for any children of the marriage, including support. Read more about divorce in Ontario.

Changing a Child Support Amount Later

Child support is not fixed forever. A meaningful change — commonly in either parent's income, in parenting time, or a child becoming independent — can be grounds to change the amount going forward. Parents can agree to a new amount in writing, or, where they cannot agree, ask a court to change an existing order or filed agreement.

Read more about changing a support amount and changing or enforcing a family court order.

Enforcing Child Support: The Family Responsibility Office

Ontario's Family Responsibility Office, generally known as the FRO, is the provincial agency responsible for collecting and enforcing court-ordered child and spousal support, as well as support in a written agreement filed with the court. Once registered, the FRO can generally collect payments directly from the paying parent, including by directing an employer to deduct support from wages.

Where a paying parent falls behind, the FRO generally has further enforcement tools without needing a fresh court order each time — part of why filing an agreement with the court, rather than relying on an informal arrangement, can matter. Read more about enforcing child support.

A General Step-by-Step Pathway to Sorting Out Child Support

This is a general outline only. Your own steps may vary.

  1. Confirm which Guidelines likely apply

    Generally federal if divorcing, or Ontario's own if not.

  2. Gather income information for both parents

    Recent tax returns and notices of assessment are a common starting point.

  3. Estimate the general parenting-time arrangement

    This affects whether a shared-parenting approach applies.

  4. Identify any potential section 7 expenses

    Such as childcare, health-related costs, or post-secondary education.

  5. Try to reach a written agreement, if possible

    Often with negotiation, mediation, or independent legal advice for each parent.

  6. File the agreement or order with the court

    Generally needed for the Family Responsibility Office to enforce it later.

  7. If parents cannot agree, consider a court application

    See starting a family court case.

  8. Revisit the amount as circumstances change

    Such as an income change, a parenting-time change, or a child becoming independent.

Common Mistakes and Misunderstandings About Child Support

  • Assuming child support ends automatically the moment a child turns 18
  • Assuming equal or near-equal parenting time always means no support is owed
  • Relying on an informal, unfiled agreement instead of filing it with the court
  • Overlooking self-employment or corporate income when estimating income for support
  • Treating section 7 expenses as automatically split down the middle rather than by income
  • Waiting a long time to raise an income change or unpaid support

Frequently Asked Questions

How is the amount of child support calculated in Ontario?

The basic amount is generally calculated using a "table" set out in the applicable Child Support Guidelines, based on the paying parent's income, the number of children, and the province of residence. Special or extraordinary expenses may be added on top, shared roughly by income. See How the Basic Amount Is Generally Calculated.

Does income for child support include bonuses or self-employment income?

Generally, yes. The Guidelines start from a broad definition of income, commonly based on total income reported for tax purposes, and can include bonuses, overtime, and self-employment earnings. Self-employment and certain other income sources can involve additional adjustments, which is often where disputes arise.

What happens if the paying parent's income changes?

A meaningful, ongoing change in either parent's income can be grounds to ask for the support amount to be recalculated or changed going forward. Many separation agreements and court orders also require parents to exchange updated income information each year for this reason. See Changing a Child Support Amount Later.

Does 50/50 parenting time mean no child support is paid?

No. Even when parenting time is shared close to equally, child support is often still payable, generally reflecting any difference between the parents' incomes and the increased costs of maintaining two homes for the child. See Shared Parenting and Child Support above.

Is child support taxable income?

Generally, no. Under current federal tax rules, child support payments made under an agreement or order dated on or after May 1, 1997 are not taxable to the parent who receives them and not tax-deductible for the parent who pays them.

What can I do if the other parent refuses to pay child support?

If the support is set out in a court order, or in a written agreement that has been filed with the court, it can generally be registered with Ontario's Family Responsibility Office for enforcement. See Enforcing Child Support: The Family Responsibility Office above.

Does child support cover post-secondary education costs?

It can. Post-secondary tuition is commonly treated as a section 7 expense shared between the parents, and basic support may also continue while a child remains a "child of the marriage" in full-time school. See Special and Extraordinary Expenses and Child Support for Adult Children.

Can parents agree to a different amount than the Guidelines suggest?

Parents can agree to a different amount, but because support is legally the child's right, a court reviewing the agreement will generally want it to still be reasonable for the child. See Child Support and Separation Agreements.

Is child support the parent's right or the child's right?

Courts describe child support as the right of the child, not the parent who receives it. This is part of why a parent generally cannot simply waive or bargain away a child's entitlement to support on their own. See What Is Child Support? above.

Does child support automatically end when a child turns 18?

Not necessarily. Support can continue past the age of majority for a child who remains a "child of the marriage," such as one still in full-time school or unable to withdraw from parental charge due to illness or disability. See Child Support for Adult Children.

Do unmarried parents have to pay child support too?

Yes. Parents who were never married, or are married but not seeking a divorce, generally have the same basic obligation, addressed through Ontario's own Guidelines under the Family Law Act rather than the federal Divorce Act. See Which Guidelines Apply.

What are section 7, or "special or extraordinary," expenses?

Additional costs, such as childcare, uninsured health-related expenses, and post-secondary education, generally shared between parents roughly by income, on top of the table amount. See Special and Extraordinary Expenses.

Can I get child support for past periods (retroactive support)?

Retroactive child support is a recognized concept, and courts have confirmed such claims are not treated as rare or exceptional. How far back an award can reach depends on the circumstances, including when notice was given. See Retroactive Child Support above.

Do I need to go to court to change a child support amount?

Not always. Parents can agree in writing to change support without going to court, though filing a written agreement with the court is generally what allows it to be enforced later. A court process is generally needed when parents cannot agree. See Changing a Child Support Amount Later above.

What happens if I disagree with how much child support I've been asked to pay?

You can raise a disagreement about income, the applicable Guidelines, or special expenses through negotiation, mediation, or, if needed, a family court application, rather than simply refusing to pay. Unpaid amounts can still be enforced in the meantime.