When each parent has the child at least 40 per cent of the time over a year, Ontario child support is not simply the table amount. Section 9 of the child support guidelines requires the court to look at both parents' table amounts, the higher costs of running two homes for the child, and each household's circumstances.
How shared parenting changes child support in Ontario
Most child support starts with one number: the amount in the federal table for the paying parent's income and the number of children. Shared parenting is the main exception. Once each parent exercises parenting time for not less than 40 per cent of the time over the course of a year, section 9 of the Ontario Child Support Guidelines replaces the simple table rule with a broader assessment. The Federal Child Support Guidelines contain the same rule for divorcing parents. For the full picture of support after separation, see our child and spousal support page.
In practice, a shared parenting support question usually moves through these steps:
- Confirm the parenting schedule. Write down the actual schedule over a full year: regular weeks, holidays, summer and special days.
- Test the 40 per cent threshold. Each parent must have the child at least 40 per cent of the time over the year. The guidelines do not set one counting method, so the way time is counted can itself be disputed.
- Find both incomes. Unlike the usual case, both parents' guideline incomes matter from the start; see what counts as income for support.
- Look up both table amounts. Each parent's table amount is read for the number of children, as if each were paying the other.
- Weigh the other two factors. The court considers the increased costs of shared parenting time and the condition, means, needs and other circumstances of each parent and child.
- Add section 7 expenses. Special or extraordinary expenses are still shared in proportion to income, on top of the section 9 amount.
Shared, split and majority parenting time compared
| Arrangement | What it means under the Ontario guidelines | How the base amount is found |
|---|---|---|
| Majority parenting time | One parent has more than 60 per cent of parenting time over a year (s. 2(1) definition) | The table amount for the other parent's income (s. 3) |
| Shared parenting time | Each parent has the child at least 40 per cent of the time over a year (s. 9) | Both table amounts, increased costs of the shared arrangement, and each household's circumstances |
| Split parenting time | Two or more children, and each parent has the majority of time with at least one child (s. 8) | The difference between what each parent would pay the other |
How section 9 works in practice
Section 9 does not contain a formula. It lists three things the court must take into account, and leaves the weighing to the court.
Both table amounts. A common starting point is to compare what each parent would pay the other under the tables and look at the difference, often called a set-off. Because the tables are not straight-line percentages, two parents with similar incomes may have table amounts that nearly cancel out, while parents with very different incomes may end up with a meaningful difference.
Increased costs of shared parenting. Two homes for one child often cost more than one: two bedrooms, duplicate clothing and equipment, more travel. Evidence of actual spending in each home helps the court decide whether the set-off should be adjusted.
Condition, means, needs and circumstances. The court can look at each household's resources and the child's standard of living in each home. If one home would be much poorer than the other, the court may set an amount that reduces that gap.
Because shared parenting depends on the parenting arrangement, it helps to understand how Ontario now describes that arrangement. Our page on decision-making responsibility and parenting time explains the terms that replaced custody and access in 2021.
Why crossing 40 per cent matters
Below the threshold, the parent with less time usually pays the full table amount under section 3, whatever the other parent earns. Our page on how child support is calculated in Ontario walks through that standard calculation. Above the threshold, the other parent's income enters the base calculation, and the result can be much lower, or occasionally higher, depending on the incomes and the costs in each home.
Because of that difference, the 40 per cent line can become a point of conflict. Parents sometimes negotiate a schedule with one eye on support. Courts are alert to this, and a schedule that looks designed to reach the threshold, rather than to suit the child, tends to attract scrutiny. The more useful approach is to agree on the schedule that works for the child first, then apply the guidelines honestly to whatever schedule results.
It also helps to remember that section 9 does not reward equal time alone. A parent who has the children 45 per cent of the time but spends little on them may not see much change from the table amount, while a parent who carries more of the costs in both homes may.
What changes the answer
- Whether the 40 per cent threshold is met (s. 9). Falling just below 40 per cent means the usual table rule in section 3 applies. Parents sometimes disagree about whether time at school, daycare or with a caregiver counts toward one parent.
- Split parenting (s. 8). When each parent has the majority of time with a different child, support is the difference between what each would pay for the children in the other's care.
- Section 7 expenses. Child care, health, education and extraordinary activities are still shared by income; see special or extraordinary expenses.
- Undue hardship (s. 10). A section 9 amount can be changed for undue hardship, but only if the household claiming it would not have the higher standard of living. See undue hardship.
- Agreements (Family Law Act, s. 33(14)). Parents can agree on an amount, and a court may approve a different amount on consent if reasonable arrangements have been made for the child.
- The child's best interests come first. A parenting schedule is set for the child, not to reach a support threshold. Courts decide parenting time on the best interests factors; see how courts decide a child's best interests.
A worked example
For example, imagine parents in Toronto with two children on a week-on, week-off schedule, so each parent has the children about half the time. One parent earns $100,000 and the other earns $70,000. Each parent's table amount for two children is looked up in the official 2025 table for Ontario. The difference between those two amounts is the set-off: the higher earner pays the difference to the lower earner.
The court then considers the other two factors. Suppose the lower-earning parent shows they pay for most of the children's clothing, school supplies and activity equipment in both homes, and their home has a much tighter budget. The court may set an amount above the straight set-off to reflect those costs and the gap between households. If instead the higher earner pays most of the duplicated costs directly, the court may set an amount at or below the set-off. Section 7 expenses, such as the children's after-school care, would still be shared about 59 to 41 per cent by income ($100,000 and $70,000 out of $170,000).
This example is hypothetical. It shows the method, not a predicted result.
Common mistakes in shared parenting support
- Assuming equal time means no support. Where incomes differ, a payment from the higher earner is common even with a 50/50 schedule.
- Counting time loosely. Keep a calendar of overnights and handovers for the full year. A schedule on paper is not always the schedule followed.
- Arguing about time to change support. Courts set parenting time for the child's best interests. Pushing for more time to reach 40 per cent, without regard to the child, rarely helps.
- Forgetting the costs evidence. Section 9 asks about the increased costs of the shared arrangement. Budgets and receipts from each home make that factor real.
- Skipping disclosure. Both incomes matter in shared parenting, so both parents must disclose; failing to can lead to imputed income and costs.
- Leaving the schedule change undocumented. If time moves above or below 40 per cent, update the agreement or order so support reflects the new arrangement.
What to do this week
- Print a 12-month calendar and mark each day and overnight the children spend with each parent.
- Gather your last three tax returns and notices of assessment, and ask for the other parent's.
- Look up both parents' table amounts in the official 2025 federal look-up.
- List the child-related costs each home pays, including duplicated items and travel between homes.
- List any section 7 expenses with receipts.
- Book a free consultation with us to test the 40 per cent count and the likely range before you negotiate.
Frequently asked questions
Is 40 per cent counted in days or overnights?
The guidelines only say "not less than 40 per cent of the time over the course of a year". They do not prescribe days, overnights or hours, so the counting method can be argued. A clear record of the actual schedule is the best evidence.
Does shared parenting affect spousal support too?
Child support is decided first, and the Family Law Act gives child support priority over spousal support (s. 38.1). The child support amount then feeds into any spousal support calculation; see how spousal support is worked out.
What if one parent has 40 per cent with one child but not another?
The threshold is applied with respect to a child. Where children live on different schedules, the arrangement may be part shared, part majority or split, and each child's time is looked at separately.
Can we change support if the schedule changes?
Yes. A change in parenting time that would produce a different result under the guidelines is a change in circumstances. The order or agreement can be varied, as our article on changing child support payments explains. If spousal support is also paid, it may need a fresh look at the same time; see changing or ending spousal support.
Do both parents have to share income every year?
Where both incomes were used to set support, each must provide updated tax information every year after the order (s. 24.1). See yearly income disclosure.
Does the Child Support Service handle shared parenting cases?
The online service sets up or updates child support using income information. Whether a given shared parenting case is eligible depends on the service's own rules, so check with the service before applying, or speak with a lawyer about the right route.