Child Support in Canada

Child support is not a negotiable favour — it is a legal obligation set by a formula. The amount is determined by the paying parent's income, the number of children, and the province of residence. Understanding how the formula works, what expenses fall outside it, and how orders are enforced prevents costly mistakes for both parents.

What Child Support Covers — and What It Does Not

The base monthly amount covers ordinary day-to-day costs: food, clothing, shelter, and basic activities. It does not cover everything a child needs.

Included in the base amount:

• Groceries and household costs
• School supplies and basic clothing
• Standard recreational activities

Not included — covered separately as section 7 expenses:

• Licensed childcare and daycare
• Medical and dental costs not covered by insurance
• Post-secondary tuition and residence fees
• Extracurricular activities (if reasonable given the family's income)
• Health-related expenses: orthodontics, therapy, prescription glasses

Section 7 expenses are shared proportionally based on each parent's income — not split 50/50. If one parent earns $80,000 and the other earns $40,000, the higher earner pays two-thirds of section 7 costs.

How the Base Amount Is Calculated

The Federal Child Support Guidelines set the base amount using three variables:

1. The paying parent's gross annual income (Line 15000 of the T1 tax return) 2. The number of children 3. The paying parent's province of residence

The tables produce a fixed monthly amount. There is no discretion at this stage — the table amount applies unless the court finds a specific reason to depart from it.

Sample amounts — Ontario, Federal Child Support Guidelines:

Amounts differ by province. A parent earning $80,000 in Alberta pays a different table amount than one earning $80,000 in Ontario. The Department of Justice publishes the full tables; amounts are updated periodically to reflect current economic data.

Income over $150,000: The Guidelines tables stop at $150,000. Above that threshold, the court determines the amount by starting with the table amount for $150,000 and adding an additional sum based on the child's reasonable needs and the family's pre-separation standard of living.

Special and Extraordinary Expenses (Section 7)

Section 7 of the Federal Child Support Guidelines covers expenses that are necessary and reasonable given the family's circumstances. Courts apply a two-part test: is the expense necessary? Is it reasonable given both parents' incomes?

How section 7 cost-sharing works in practice:

If Parent A earns $90,000 and Parent B earns $30,000, their combined income is $120,000. Parent A's share is 75%; Parent B's share is 25%. If daycare costs $1,200/month, Parent A pays $900 and Parent B pays $300 — regardless of which parent physically pays the daycare provider.

Common section 7 disputes:

• Extracurricular activities: Courts look at whether the activity was part of the child's life before separation and whether the cost is proportionate to the parents' incomes. Hockey at $4,000/year may be reasonable for a family with combined income of $200,000; less so at $80,000.
• Post-secondary education: Courts consider the child's academic performance, the program's cost, and whether the child contributes through part-time work or student loans. There is no automatic obligation to fund any program the child chooses.
• Uninsured medical expenses: Generally straightforward if the expense is prescribed by a regulated health professional.

Shared Parenting and the 40% Rule

When a child spends at least 40% of their time with each parent, the standard table amount does not automatically apply. The court has discretion to adjust the amount using one of three approaches:

1. Set-off method: Each parent calculates what they would pay if the other were the sole recipient, then the higher earner pays the difference. 2. Increased table amount: The court increases the table amount to reflect the higher costs of maintaining two separate households for the child. 3. Hybrid approach: A combination based on the child's actual documented expenses.

Example — set-off method:

• Parent A earns $90,000; Ontario table amount for 1 child: ~$820/month
• Parent B earns $50,000; Ontario table amount for 1 child: ~$450/month
• Set-off result: Parent A pays Parent B $370/month

The 40% threshold is calculated over the course of a full year, not week by week. A parent who has the child for 146 days per year (40% of 365) meets the threshold. Courts look at actual time spent, not what the parenting order says on paper.

The leading case is Contino v Leonelli-Contino [2005] SCC 63, which confirmed that the set-off method is the starting point but not the only option — courts must also examine the actual costs each parent incurs.

How Income Is Determined — Including Imputed Income

Child support income is not always what a parent reports on their tax return. Courts can impute income — attribute a higher income than what the parent actually earns — in several situations:

• The parent is voluntarily unemployed or underemployed without reasonable explanation
• The parent controls a corporation and takes income as dividends rather than salary to reduce the apparent income figure
• The parent has unreported cash income
• The parent recently left a higher-paying position without justification

Corporate income: If a parent owns a corporation, courts look at both the salary drawn and the retained earnings left in the company. A parent who pays themselves $60,000 but leaves $100,000 in the corporation may have income imputed at a significantly higher level.

Income documents courts typically require:

• Last 3 years of T1 tax returns (all pages, including schedules)
• Last 3 years of Notices of Assessment from CRA
• Recent pay stubs (last 3 months)
• Corporate financial statements if self-employed or incorporated
• T4 slips, T5 slips, and any other income slips

Changing a Child Support Order

Child support orders are not permanent. Either parent can apply to vary the order when there is a material change in circumstances — a change that, had it existed at the time of the original order, would have resulted in a different amount.

What qualifies as a material change:

Annual income disclosure: Under the Federal Child Support Guidelines, both parents are required to exchange income information annually — even without a court order requiring it. In practice, many parents skip this, which leads to support amounts that become outdated as incomes change.

Retroactive child support: Courts can order retroactive support going back up to three years before the date of formal notice (DBS v SRG [2006] SCC 37). If a paying parent's income increased and they did not disclose it, the receiving parent can claim the difference retroactively. The court weighs whether the paying parent had a reasonable excuse for the non-disclosure and whether retroactive payment would cause undue hardship.

Enforcement Across Canada

Child support orders are enforceable through provincial enforcement programs. Registration is automatic in most provinces when an order is made — the paying parent does not have to agree to it.

Federal enforcement tools: The federal government can intercept federal payments — income tax refunds, EI benefits, CPP payments — and deny or revoke passports for parents who owe more than $3,000 in arrears.

Arrears: Unpaid child support accumulates as a debt. There is no limitation period on collecting child support arrears in most provinces — a parent can pursue arrears years after they accrued. Interest accrues on arrears at the rate specified in the court order or provincial legislation.

How Long Child Support Lasts

Child support continues until the child is no longer a "child of the marriage" under the Divorce Act. This is not simply age 18.

A child remains a "child of the marriage" if they are:

• Under the age of majority (18 or 19, depending on the province) and have not withdrawn from parental charge
• Over the age of majority but unable to withdraw from parental charge due to illness, disability, or full-time post-secondary education

Post-secondary education: Courts regularly order support to continue while a child is enrolled in university or college. The amount may be adjusted to reflect the child's own income from summer employment, scholarships, or student loans, and whether the child lives at home or in residence. There is no automatic cutoff at age 18 or 22.

When support ends:

• Child completes education and becomes financially self-sufficient
• Child marries or enters a common-law relationship
• Child is adopted by another person
• Court order specifies an end date and that date arrives