Grounds for Full Custody of a Child in Canada

Seeking grounds for full custody of a child in Canada requires a clear understanding of the federal Divorce Act (R.S.C., 1985, c. 3 (2nd Supp.)) and how courts apply the best-interests test. This guide explains the legal framework, the factors courts weigh, and how documented evidence supports your application. If you need help gathering evidence for a contested parenting application, contact a licensed private investigator as early as possible in the process.

What full custody means under Canada’s Divorce Act

As of March 1, 2021, amendments to Canada’s Divorce Act (R.S.C., 1985, c. 3 (2nd Supp.)) — enacted through Bill C-78 (S.C. 2019, c. 16) — replaced the terms “custody” and “access” with “parenting time” and “decision-making responsibility.” The change was intended to reduce the adversarial “winner-loser” framing of older custody language and to centre children’s needs in the proceedings. You can review the legislative objectives behind Bill C-78 on the Department of Justice Canada website.

Under the amended Act, there are two distinct concepts to understand:

Decision-making responsibility covers who makes significant choices about the child’s education, health care, religion, and extracurricular activities. This can be shared jointly or assigned solely to one parent.

Parenting time covers where and with whom the child lives on a day-to-day basis. One parent may have primary parenting time (the child lives mainly with them) or parenting time can be roughly equal between both parents.

Rather than discussing “full custody,” you will now be discussing whether you are seeking sole or primary parenting time and/or sole decision-making responsibility. Sole decision-making responsibility — where one parent makes all major decisions about the child — requires demonstrating that the arrangement serves the child’s best interests under s. 16 of the Divorce Act. Courts do not presume shared arrangements are always appropriate; the best-interests analysis is case-specific.

What ‘best interests of the child’ means under the Divorce Act

The best-interests standard in Divorce Act s. 16(3) is the sole test courts apply when making any parenting order. No other consideration overrides it. The Act sets out a non-exhaustive list of factors:

• The child’s physical, emotional, and psychological safety, security, and well-being
• The child’s needs, given their age and stage of development, including the need for stability
• The nature and strength of the child’s relationship with each parent, siblings, and other significant persons
• Each parent’s willingness to support the child’s relationship with the other parent
• The history of care of the child
• The child’s cultural, linguistic, religious, and spiritual upbringing and heritage (including Indigenous heritage)
• Any civil or criminal proceedings relevant to the child’s safety or well-being
• The child’s own views and preferences, given appropriate weight based on age and maturity
• Each parent’s ability to communicate and cooperate on child-related matters

A court must not consider past conduct of a parent unless it is relevant to how that parent exercises parenting responsibilities — this prevents either party from turning proceedings into a character attack unrelated to the child’s welfare.

Grounds courts consider for sole decision-making responsibility

Under s. 16(3) of the Divorce Act (R.S.C., 1985, c. 3 (2nd Supp.)), courts weigh a non-exhaustive list of factors when determining parenting arrangements, all in service of the child’s best interests. Circumstances that may support an order for sole decision-making responsibility include:

1. Established family violence and its impact on the child’s safety — The 2021 amendments added s. 16(4), which requires the court to consider specific factors when family violence is present: the nature and severity of the violence, whether it was directed at the child, any pattern of coercive or controlling behaviour, and whether safety measures such as a protection order are in place.
2. Severe substance abuse or mental health impairment — A parent whose addiction or untreated mental health condition compromises their ability to meet the child’s needs on a consistent basis.
3. Long-term absence or lack of involvement — A parent who has been chronically absent from the child’s life, or who shows a sustained pattern of non-engagement with the child’s day-to-day care.
4. Irresponsible exercise of decision-making responsibility — A demonstrated pattern of making unilateral major decisions about the child contrary to court orders, or decisions that harm the child’s interests.
5. Criminal history or conduct that negatively affects the child — Convictions or ongoing conduct that expose the child to risk or undermine the child’s security.
6. Unwillingness to support the other parent’s relationship with the child — A parent who actively undermines, interferes with, or alienates the child from the other parent may be found to act contrary to the child’s best interests.
7. The child’s own views and preferences — Courts must consider what the child themselves expresses about their situation, with weight proportional to the child’s age and maturity.

Courts do not award sole decision-making responsibility as a default or on the basis of a parent’s gender. Each case turns on the specific evidence about what arrangement best serves this particular child. For a factual overview of how courts have historically resolved these applications, see the Department of Justice Canada JustFacts on child custody and access.

When shared parenting is not appropriate

Canadian courts assess each family’s circumstances individually — there is no statutory presumption in favour of equal or shared parenting time. According to the Department of Justice Canada’s Survey of Family Courts (covering 2018–2019 court orders), sole physical custody was awarded in approximately 63% of cases, shared physical custody in 31%, and joint decision-making responsibility was ordered in 61% of cases. These figures reflect the most recent published cycle and are the primary Canadian source for how courts actually resolve parenting-time disputes.

Shared parenting is not appropriate — and courts will generally decline to order it — in circumstances that include:

Active family violence. When one parent has perpetrated violence against the other parent or the child, a shared arrangement that forces ongoing parental interaction can place victims at continued risk. Courts applying Divorce Act s. 16(4) must address this explicitly. Our domestic violence investigations team handles court-admissible documentation specifically structured for s. 16(4) findings.

Entrenched inability to cooperate. Shared decision-making requires a baseline capacity for communication between parents. Where conflict is so severe that all meaningful co-parenting has broken down — and where court-ordered dispute resolution has failed — judges may conclude that one-parent decision-making better serves the child.

Geographic impracticality. When one parent has relocated, or proposes to relocate, so that equal-time sharing is physically unworkable, the court must fashion an arrangement that reflects reality rather than an aspiration.

A parent’s serious impairment. Active addiction, untreated psychiatric illness, or other conditions that prevent a parent from exercising safe and consistent parenting cannot be managed through a shared framework.

If you are concerned about your child’s safety in the other parent’s care, document your observations carefully and speak to a licensed PI about evidence that can be placed before the court.

Decision-making responsibility vs parenting time: key differences

Under the 2021 Divorce Act amendments, decision-making responsibility and parenting time are legally distinct. A parent can have primary parenting time without sole decision-making responsibility, or vice versa.

Decision-making responsibility and parenting time can be mixed and matched. For example, one parent may have sole decision-making responsibility while both share roughly equal parenting time. Always confirm with a family law lawyer which combination best reflects your child’s needs and your specific circumstances.

How to apply for sole decision-making responsibility in Canada

Divorce proceedings are governed by the federal Divorce Act. Separate-but-married-or-common-law parents who are not divorcing may apply under provincial family law legislation instead. The general procedural steps in a divorce context are:

1. Consult a family law lawyer. Sole decision-making responsibility applications are complex. A lawyer will assess whether your grounds are sufficient, advise on the strength of your evidence, and guide you through the applicable court rules in your province.
2. File your application. In most provinces this means filing a Statement of Claim or Application for divorce with the applicable family court, including a request for a parenting order under the Divorce Act.
3. Serve the other parent. The responding parent must be formally served and given the opportunity to file their own materials.
4. Complete financial disclosure. Parenting applications are typically combined with child-support proceedings, which require full financial disclosure from both parties.
5. Attend case conferences and motions. Courts in most provinces require parties to attend a case conference before trial. Interim parenting orders may be sought at this stage if the child’s safety is at immediate risk.
6. Gather and disclose your evidence. Affidavits, police reports, medical records, school records, and any evidence gathered by a licensed private investigator must be disclosed to the other party and the court according to the rules of your jurisdiction.
7. Consider mediation or collaborative law. Courts generally expect parties to attempt dispute resolution before trial. However, in cases involving family violence, mediation may not be appropriate.
8. Trial or consent order. If the parties reach agreement, a consent order is filed. If not, the matter proceeds to trial, where a judge applies the best-interests factors under Divorce Act s. 16(3) to all evidence and makes a final parenting order.

The role of a child custody evaluator

In contested parenting cases involving a serious clinical issue, courts may order a formal assessment to assist in evaluating the child’s best interests. In Ontario, this process is governed by s. 30 of the Children’s Law Reform Act (R.S.O. 1990, c. C.12). A Section 30 assessment is typically ordered when the dispute turns on a concern about a parent’s mental health, substance use, or capacity to meet the child’s needs — not as a routine step in every contested case.

A Section 30 assessor (typically a registered psychologist or psychiatrist) interviews the child, both parents, and relevant third parties such as teachers, grandparents, or family members. The assessor reviews health, school, and counselling records, and may administer psychological testing where the specific clinical question warrants it. Psychological testing is done case-by-case, not as a standard component of every assessment.

Separately, the Office of the Children’s Lawyer (OCL) provides publicly funded assessments in appropriate cases, typically where the case raises concerns about the child’s interests rather than a specific clinical question about a parent’s capacity.

The resulting assessment report carries significant weight in court, and courts treat these reports as highly persuasive expert evidence in contested custody proceedings.

Types of evidence a private investigator can gather for family court

A licensed private investigator can gather documented evidence that directly addresses the best-interests factors courts apply under Divorce Act s. 16(3). The following types of evidence are commonly requested in contested parenting applications:

• Surveillance observations of a parent’s behaviour during parenting time: substance use, unsafe environments, exposure of the child to known risks, or failure to supervise
• Timestamped photographic and video evidence of conditions in the child’s home environment or during exchanges
• Vehicle and location monitoring (where lawfully conducted) to verify compliance with court-ordered parenting schedules or to document violations of parenting orders
• Documentation of third-party contacts — identifying adults whom a parent regularly exposes the child to, particularly where criminal history or family-violence history is alleged
• Witness canvassing to identify and obtain statements from individuals with relevant knowledge of the child’s situation
• Social media and digital evidence collection in a forensically sound manner, preserving metadata required for court admissibility

All evidence gathered by a licensed PI must comply with applicable privacy legislation and the procedural rules of the court where it will be tendered. Work product is typically provided to your counsel in a form designed to be attached to an affidavit or introduced through the PI’s own viva voce testimony.

If you are navigating a contested parenting application, contact Discreet Investigations to discuss how licensed surveillance and investigation services can support your case. Our team is Licensed · Insured · Bonded and operates across Canada. Call us at +1 (888) 680-0036 or visit our child custody investigation service page to learn more. You may also find our guide on parental abduction in Canada useful if your concern involves a parent removing the child without consent. For broader data on Canadian divorce and custody trends — including separation rates, primary-care patterns, and the share of contested cases — see our compilations of child custody statistics in Canada, Canadian divorce statistics, and the family law research hub.