If you are separating or divorcing and trying to figure out how parenting will work going forward, you have probably come across the term “shared custody.” It is one of the most commonly asked-about concepts in family law, and also one of the most misunderstood.
This guide explains:
- what shared custody means in Ontario
- how it differs from joint custody and sole custody
- what the 40% rule is and why it matters
- and how a shared custody arrangement affects child support.
Whether you are just starting to think through your options or already in negotiations, understanding these basics will help you ask better questions and make more informed decisions.
This page is provided for general informational purposes only and does not constitute legal advice. Reading this content does not create a lawyer-client relationship with RPB Family Law. Parenting arrangements, parenting time, decision-making responsibility, and child support outcomes in Ontario depend on the specific facts of each case, including the child’s best interests, the family’s circumstances, and any existing agreement or court order. You should speak with a qualified Ontario family lawyer for advice about your particular circumstances.
The short answer: what shared custody means
Shared custody is a parenting arrangement in which a child spends at least 40 percent of their time living with each parent. After separation or divorce, this structure allows both parents to maintain a meaningful relationship with the child.
Shared custody refers specifically to the physical dimension of parenting, where the child lives and how much time they spend with each parent, rather than who makes major decisions about the child’s upbringing. The child splits their time between two homes on a regular, structured schedule.
If you are trying to decide whether a shared custody arrangement is realistic, fair, and workable in your circumstances, RPB Law can help you evaluate parenting time, support implications, and the legal framework that may apply. Our team provides practical guidance for Ottawa families working through parenting plans, separation agreements, and child-related disputes under Ontario family law.
Learn more about child custody in Ontario
What Ontario calls “shared custody” today
Ontario family courts no longer use the word “custody” as the primary legal term for married parents going through a divorce.Since March 2021, the federal Divorce Act replaced “custody and access” with two new concepts for divorcing spouses: parenting time and decision-making responsibility.
- Parenting time refers to the periods when a child is in a parent’s care.
- Decision-making responsibility covers who makes major choices about the child’s health, education, religion, and welfare.
The Children’s Law Reform Act governs unmarried parents in Ontario.
Learn more about parenting time and decision-making responsibility in Ontario.
Shared custody, joint custody, and sole custody
These three terms are often used interchangeably, but they mean different things in Ontario family law.
Shared custody
Shared custody is about time. It refers to a parenting schedule where each parent has the child at least 40 percent of the time, living across two homes. It does not say anything specific about who holds decision-making authority.
Joint custody
Joint custody (or joint decision-making responsibility under the current Divorce Act) is about decisions. Both parents share decision-making authority over major aspects of the child’s life: schooling, medical care, religious upbringing, and extracurricular activities.
Parents can have joint decision-making without shared physical custody, for example, one parent may be the primary residence parent while both share legal decision-making responsibility. This is a common arrangement where parents negotiate a parenting plan that gives one parent primary care while maintaining equal parenting time in terms of decision-making involvement.
Joint physical custody, by contrast, combines both shared time and shared decision-making, and is essentially what most people mean when they use “shared custody” in everyday conversation. In co-parenting arrangements that function well, both joint and shared models typically require parents to communicate regularly, cooperate on scheduling, and put the child’s needs ahead of their own preferences.
Sole custody
Sole custody concentrates both physical care and decision-making authority with one parent. The other parent may still have parenting time and access rights, but the custodial parent has the final say on major decisions. Sole custody arrangements are generally reserved for situations involving serious concerns about the other parent’s ability to cooperate or keep the child safe.
Split custody
Split custody is a separate and less common arrangement where, in families with more than one child, each parent has primary care of at least one child. Courts generally avoid separating siblings, but it sometimes reflects the practical reality of older children’s preferences and circumstances.
Parallel parenting
Parallel parenting is sometimes ordered in high-conflict situations where parents cannot cooperate directly. Each parent makes decisions independently during their own parenting time, with a structured framework minimizing contact between the adults.
The 40% rule: what it means and how it is calculated
The 40 percent threshold is the dividing line between primary parenting time and shared parenting time under the Federal Child Support Guidelines. Once a parent has the child for at least 40 percent of the time, roughly 146 days per year, the legal framework for calculating child support changes significantly under Section 9 of the Child Support Guidelines.
Reaching the 40% rule matters for more than just terminology. It triggers a different calculation method for child support, which can substantially affect what each parent pays or receives. For this reason, both the threshold itself and how it is measured are frequently contested.
Counting days vs. counting hours
Ontario courts do not apply a single fixed formula for measuring whether the 40 percent threshold has been met. Some judges prefer a strict day-count approach; others use an hourly calculation. The hourly method is generally favored in Ontario case law, and it counts actual hours of care and control, not just overnight stays.
The time the child spends in school or daycare is typically credited to the custodial parent, unless the non-custodial parent drops off and picks up. Overnights count in full, but daytime-only visits are counted by the hour.
If you believe you are approaching or exceeding the 40% threshold, it is worth keeping a detailed record of your parenting time. Courts have found small differences in calculated time to be determinative, and good documentation protects your position.
How shared custody affects child support in Ontario
One of the most significant practical consequences of shared custody is its effect on child support. Under the standard rules in the Federal Child Support Guidelines, child support is calculated based primarily on the payor parent’s income, with the recipient being the parent who has the child the majority of the time. When shared parenting time applies, that is, when each parent has the child at least 40 percent of the time, the formula changes.
For detailed information on how support is calculated generally, our guide on what is child support in Ontario covers the fundamentals clearly.
The set-off method explained
When shared parenting time applies, courts use a set-off approach rather than the standard table amount. Each parent calculates the amount they would owe based on their own income under the guidelines. The parent with the higher income then pays the difference to the lower-income parent. This set-off calculation recognizes that both parents are directly bearing the costs of raising the child during their respective parenting time.
The result is that child support payments in a shared parenting arrangement are typically lower than in a primary-residence situation, but they are rarely zero, even when parenting time is close to equal.
- Calculate the table amount each parent would owe based on their individual income.
- Subtract the lower amount from the higher amount.
- The parent with the higher income pays that difference to the other parent.
- The court may also consider special or extraordinary expenses and adjust the final child support order accordingly.
Can shared custody reduce child support payments?
In short, yes, but not automatically, and not without meeting the 40% threshold first. Courts have also made clear, following Supreme Court of Canada guidance, that simply meeting the 40% threshold does not guarantee a reduction. The court must be satisfied that the proposed reduction would not cause a noticeable decline in the child’s standard of living. Children should not bear the financial consequences of a change in parenting arrangements, and judges will assess both parents’ means, needs, and actual spending on the child.
If you are navigating these calculations, speaking with child support lawyers in Ottawa who understand the shared parenting context can help you avoid costly surprises.
Common shared custody schedules
There is no single correct shared parenting schedule. What works for one family may not work for another, and courts encourage parents to reach their own parenting agreements rather than having a schedule imposed. The most important factors are geographic proximity, the child’s school and activity commitments, the child’s age and temperament, and the parents’ work schedules.
- Week-on week-off: Each parent has the child for a full week, then alternating weeks with the other parent. This is a common shared parenting schedule and works well for school-aged children who benefit from longer, more predictable periods in each home.
- 2-2-3 rotation: The child spends two days with one parent, two days with the other, then three days with the first parent, alternating each week. This reduces the longest stretch without seeing either parent and suits younger children who need more frequent contact.
- 3-4-4-3 schedule: Similar to 2-2-3 but with slightly longer blocks. One parent has the child for three days, the other for four, then the split reverses the following week.
The parenting plan should be detailed enough to cover holidays, school breaks, special occasions, and how both parents will communicate about the child’s day-to-day needs. A well-drafted parenting plan reduces conflict and gives everyone, including the children, a stable, predictable routine. It should also include a process for reviewing the schedule as circumstances change over time.
When courts order shared parenting time in Ontario
Ontario family courts do not automatically favour shared custody arrangements. The guiding principle in every custody dispute is the best interests of the child, not the preferences of the parents, and not a presumption that equal time is always better.
Factors courts consider
When assessing whether shared parenting time serves the child’s best interests, the Ontario family court looks at:
- The quality of each parent’s relationship with the child and the child’s emotional security with each
- The ability of both parents to cooperate and communicate effectively about the child’s needs
- The involvement of both parents in the child’s life before separation
- The child’s stability, routine, and connection to school, community, and extended family
- The proximity of the two homes to each other and to the child’s school
- The child’s age, maturity, and expressed preferences (given appropriate weight)
- Any relocation concerns that could affect the practicality of shared arrangements
Where parental conflict is manageable, and both parents demonstrate genuine commitment to the child’s well-being, courts may approve or order shared parenting-time arrangements where the evidence shows the arrangement is in the child’s best interests. If cooperation is lacking, a judge may lean toward primary residence with one parent and structured parenting time for the other, or, in some cases, parallel parenting.
When shared custody is not appropriate
Shared parenting time is not appropriate in every situation. Courts will not order or approve a shared arrangement where:
- There is a credible history of abuse or domestic violence, including family violence directed at a child, partner, or other household member
- One parent poses a safety risk to the child
- The level of high conflict between the parents makes communication impossible and exposes the child to ongoing distress
- The parents live too far apart for a shared schedule to be practical for the child
In these situations, sole custody (or primary parenting time with one parent) may be in the child’s best interests. Court proceedings in contested custody cases can be lengthy and costly for both parents and children, which is why RPB Law always explores mediation and collaborative options first.
If you are concerned that shared parenting is being sought in circumstances that are not appropriate, speaking with an Ottawa child custody lawyer is an important first step.
Talk to an Ottawa family lawyer about your parenting arrangements
Shared custody questions rarely have simple answers. At RPB Law, we help Ottawa families work through these decisions with clarity and care. Whether you are drafting a separation agreement that includes a parenting plan, trying to resolve a child custody agreement without court involvement, or exploring divorce mediation as a lower-conflict path to an arrangement both parents can live with, our team is here to help. We serve families across Ottawa and surrounding communities, including Kanata, Barrhaven, Nepean, and beyond.
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