How does child support work in Ontario?
Child support is the child's right. It is paid by the parent with less parenting time to the parent with more. The basic monthly amount comes from a table based on the paying parent's income and the number of children. Some additional expenses, such as daycare and orthodontics, are shared by the parents on top of that in proportion to their income.
Key points
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Amounts come from the Child Support Guidelines. The federal tables were last updated on October 1, 2025 (Federal Child Support Guidelines).
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Married and unmarried parents have the same obligation to support their children.
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Shared parenting (at least 40% time each) and split parenting use different calculations.
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Parents must exchange income information, and the paying parent can be asked for updated income once a year.
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Child support is not taxable to the recipient or deductible by the payer.
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Who pays child support and for which children?
Usually, the parent with less parenting time pays the parent who has the child more than 60% of the time. The obligation does not depend on whether the parents were married or whether the paying parent sees the child.
Which law applies?
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Married parents getting divorced: the Divorce Act, s. 15.1. Where both parents live in Ontario, the Divorce Act applies Ontario tables, which follow the federal model.
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Unmarried parents: Ontario's Family Law Act and the Ontario Child Support Guidelines. The amounts of support are the same.
Who counts as a child?
A child under the age of majority (18 years old in Ontario), or an adult child who remains dependent because of illness, disability or "other cause". Full-time post-secondary study is the most common "other cause". Under Ontario's Family Law Act, support for an adult child is limited to one enrolled in a full-time program of education.
A step-parent who has treated a child as their own can also owe support; the amount takes into account the other parent's duty.
How much child support will I pay or receive?
The amount consists of two parts: the table amount, plus a share of any special or extraordinary expenses (also called “Section 7” expenses).
1. The table amount
The Ontario table determines a monthly payment based on the paying parent's gross annual income and number of children. You can use Justice Canada's child support lookup for an exact figure. If the income of the payor is above $150,000, the table applies to the first $150,000, and the court can set a different amount on the rest if the table figure is inappropriate.
2. What counts as income
Income is determined based on the line 15000, "Total income", on the tax return, with certain adjustments. A court can average three years of fluctuating income, include corporate income for business owners, and impute income to a parent who is intentionally under-employed or does not disclose their financials. Courts have broad discretion in deciding these issues.
3. Special or extraordinary expenses (Section 7 expenses)
On top of the table amount, parents share certain costs in proportion to their incomes, after any contribution from the child:
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child care needed for work, illness or education;
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the child's share of medical and dental insurance premiums;
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health costs over $100 a year not covered by insurance, such as orthodontics, counselling and glasses;
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extraordinary school or educational program costs;
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post-secondary education; and
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extraordinary extracurricular activities.
Any available tax credits and subsidies are deducted first.
Shared and split parenting time
1. Shared parenting arrangement: each parent has at least 40% of parenting time.
To calculate child support, determine each parent's table amount, then consider the extra costs of two homes and each household's circumstances. The difference will be paid.
2. Split parenting arrangement: each parent has the majority of time with at least one child.
Calculate each parent's table amount for the children not with them, then the difference is paid.
Hypothetical: one child, equal time, Parent A earns $90,000 and Parent B earns $50,000. The table amounts are $841 and $450, so the starting point is a set-off of $391 a month from A to B. The court then looks at actual costs and needs, so the final figure can differ. How child support is calculated has more examples.
Undue hardship
A court can depart from the Guidelines amount if a parent or child would suffer undue hardship, for example from unusually high debts or costs of parenting time. The claim fails if the claiming parent's household would still have the higher standard of living.
Can child support be changed or paid retroactively?
Yes. When support was set from the table, any change that would produce a different amount, such as a new income or a change in where the children live, is sufficient to ask for a change. The receiving parent can ask for the payer's tax returns and assessments once a year, and must share their own if their income affects the amount. A term in an agreement that limits this duty is unenforceable.
Courts can also order support retoroactively, back to the date of separation, or reduce arrears, depending on when the issue was raised and why. The Supreme Court of Canada set the framework in Michel v. Graydon, 2020 SCC 24, and Colucci v. Colucci, 2021 SCC 24.
What if child support is not paid?
Ontario's Family Responsibility Office (FRO) is a government agency that enforces support in court orders and in separation agreements filed with the court. It can garnish payor’s wages and bank accounts, suspend driver's licences and cancel passports.
When does child support end?
It does not automatically end at the age of 18. It continues while a child remains dependent, often through a first post-secondary program. It usually ends when the child finishes school, becomes self-supporting, or the agreement or order says it ends. Confirm the end date in writing rather than simply stopping payments.
Can a parenting order be changed?
Yes, if there has been a change in the child's circumstances since the order was made. You apply to vary it, or agree on new terms and ask the court to make a consent order. If the other parent will not follow the existing order, it can be enforced by the court.
From practice
Hypothetical example. Any resemblance to a real case is coincidental.
Omar owns an incorporated contracting business and pays himself a $45,000 salary. His former partner believes the company earns far more and that personal expenses run through it.
In a case like this, the T4 salary is only the starting point. The Guidelines let a court look at the company's pre-tax income and add back payments to related people, and can impute income where expenses are unreasonably deducted. Getting there usually means corporate financial statements for three years and sometimes an income report from a valuator. Settling on an agreed income early, with the documents to support it, often saves both parents the cost of that fight.
Frequently asked questions
Is child support taxable? No. Under current rules, the recipient does not report it as income and the payer cannot deduct it.
Can we agree to a different amount? Yes, but a court can set aside an amount that is unreasonable under the Guidelines, and must see reasonable arrangements before granting a divorce.
Do I pay less if I see the children more? Only once you reach at least 40% of parenting time over a year does the shared-parenting calculation apply.
Does new partner's income count? Not in the table amount. It can matter in an undue hardship claim.
Talk to a family lawyer about child support
Start with a free 15-minute call to talk through your situation and the next step. From there, we can work out the right income figure, the likely table amount and which extra expenses apply. We can calculate support, negotiate it, or ask the court to set or change it.
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A free 15-minute phone call to talk through your situation and the next step
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By phone, by video or in person at 5200 Yonge Street, Suite 200, North York
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Flat-fee, limited-scope and Legal Aid Ontario certificate work available
Book a free 15-minute call about child support · Call 416-858-1320
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Anton Mostovoy, lawyer, licensed by the Law Society of Ontario. Last reviewed: October 12, 2026
This page is general information about Ontario and federal law, not legal advice. Reading it or contacting us does not create a lawyer-client relationship. Laws and court fees change; check the date above.