The starting point: line 15000
Income for child support is the total income on the paying parent's T1 income tax return, line 15000, adjusted by Schedule III of the Federal Child Support Guidelines. That includes:
- Employment income, including regular overtime, commissions and bonuses
- Self-employment and business income
- Employment Insurance and pension income
- Investment and rental income
Adjustments (Schedule III)
Some amounts are taken out or added back so the number is fair, for example:
- Union and professional dues, and some employment expenses, are deducted
- Spousal support paid to the other parent is deducted
- Dividends count at the amount actually received, not the grossed-up tax amount
- Capital gains count at the actual gain
When the tax return is not the full picture
- Uneven income: a court can average up to three years (section 17).
- Owning a company: some of the company's pre-tax income can be included (section 18).
- Imputed income: a court can assign income to a parent who is deliberately under-employed or does not disclose (section 19).
Only the paying parent's income in a standard case
For the basic table amount in a standard case, only the paying parent's income is used. Both incomes matter for special expenses, shared custody, split custody and undue hardship.
Quebec is different
When both parents live in Quebec, the Quebec model uses both parents' incomes. Each parent's disposable income is their yearly income minus a basic deduction ($13,865 in 2026). The combined amount sets the basic parental contribution in the Quebec table. Use the Quebec calculator.
See the official text: Federal Child Support Guidelines, sections 15 to 20 and Schedule III.
Your firm, right under their number
Parents in your province see this spot the moment they get their child support result. One firm per province.
General information only, not legal advice. For your situation, speak with a family lawyer or your province's family justice services.
