A Canadian Child Support Agreement is a written contract between separated or divorced parents that establishes the financial support obligations owed to the children of the relationship. In Canada, child support is governed by the Federal Child Support Guidelines (SOR/97-175), enacted under section 26.1 of the Divorce Act (R.S.C. 1985, c. 3 (2nd Supp.)), which came into force on May 1, 1997. These Guidelines apply to divorcing spouses and have been adopted, in whole or with minor modifications, by every province and territory for use in cases involving unmarried parents under provincial family law legislation.

The cornerstone of the Guidelines is the child support table system. Each province has its own table that sets out the monthly base amount of child support based on the payor parent's gross annual income and the number of children. The tables were designed by the Department of Justice Canada using a complex economic model that considers the costs of raising children at different income levels and in different provinces, accounting for provincial and federal tax rates. The table amounts are updated periodically — most recently effective October 1, 2025 — to reflect changes in tax structures and cost of living.

For payors with income below $12,000 annually, no table amount is payable. For income between $12,000 and $150,000, the tables provide a specific monthly amount. For income above $150,000, section 4 of the Guidelines gives the court or parents discretion: they may apply the table percentage to the excess income or agree on a fixed additional amount based on the child's actual needs and the parent's ability to pay.

The 2021 amendments to the Divorce Act (Bill C-78, in force March 1, 2021) modernized terminology, replacing 'custody' and 'access' with 'parenting time' and 'decision-making responsibility.' The amendments also codified a detailed list of best-interests-of-the-child factors in section 16 and introduced provisions regarding family violence. While these changes primarily affect parenting arrangements, they also impact how child support is calculated for shared parenting time situations.

A child support agreement allows parents to formalize their obligations in a binding document without needing a court order, provided the agreement substantially complies with the Guidelines. Courts retain the jurisdiction to review and vary agreements that do not adequately provide for the children, regardless of what the parents have agreed.

A Child Support Agreement is needed whenever parents separate or divorce and have dependent children who require financial support. This includes married couples going through separation or divorce, common-law partners who have separated, and parents who were never in a conjugal relationship but share biological or adopted children.

Separating married parents who are filing for divorce under the Divorce Act require a child support arrangement — either by agreement or court order — before the divorce can be granted. Under section 11(1)(b) of the Divorce Act, the court must satisfy itself that reasonable arrangements have been made for the support of the children before granting a divorce judgment. A written child support agreement that complies with the Guidelines fulfils this requirement.

Common-law parents whose relationship has ended need this agreement because provincial family law legislation (such as the Ontario Family Law Act, the BC Family Law Act, or the Alberta Family Law Act) imposes the same child support obligations on unmarried parents as on married parents. The Federal Child Support Guidelines apply by default in most provinces for the calculation of support amounts.

This agreement is particularly important when one parent earns significantly more than the other, when the parents have a shared parenting arrangement (40% or more time with each parent) that affects the calculation under section 9 of the Guidelines, when the children have special or extraordinary expenses under section 7 (childcare, medical, educational, or extracurricular costs), or when the payor's income exceeds $150,000 and the parties need to agree on how the excess income will be treated.

Parents who have reached an agreement through mediation, collaborative family law, or direct negotiation should document their terms in a formal written agreement to ensure enforceability. Without a written agreement, verbal arrangements are difficult to enforce, and either parent may apply to court for an order that could differ from the verbal arrangement. A written agreement can also be registered with the provincial enforcement agency (such as Ontario's Family Responsibility Office or BC's Family Maintenance Enforcement Program) for automatic enforcement, including wage garnishment and interception of tax refunds.

A valid Canadian Child Support Agreement must comply with the Federal Child Support Guidelines (SOR/97-175) to be enforceable and must include specific elements to withstand judicial scrutiny.

The agreement must identify both parents with full legal names, dates of birth, and current addresses, and must list all children for whom support is payable with their full names, dates of birth, and current ages. The relationship status of the parents (married and separated, divorced, common-law, or never cohabited) determines whether the Divorce Act or provincial legislation applies and must be clearly stated.

Full income disclosure is mandatory. Each parent must disclose their gross annual income from all sources, verified by supporting documentation including CRA Notices of Assessment, T1 General tax returns, T4 slips, pay stubs, and financial statements for self-employment income. The Guidelines require income to be determined in accordance with sections 15 to 20, which address the determination of annual income. Failure to provide accurate income disclosure can result in a court imputing income under section 19.

The parenting time arrangement must be specified because it directly affects the calculation method. For primary residence arrangements, section 3 applies and the full table amount for the payor's income is payable. For shared parenting time (40% or more with each parent), section 9 applies and the court considers the table amount for each parent, the increased costs of shared parenting, and each household's conditions and needs. For split custody (different children residing primarily with different parents), section 8 requires an automatic offset of each parent's table amount.

The table amount must be stated clearly, referencing the applicable provincial table, the version of the tables used (e.g., October 2025 tables), the payor's income, and the number of children. For income over $150,000, section 4 requires the agreement to specify how the excess income will be treated.

Section 7 expenses (special or extraordinary expenses) must be addressed — either by listing the specific expenses to be shared and the proportional split based on income, or by stating that no s. 7 expenses are currently applicable. The agreement should include provisions for prior consent before incurring new expenses and for annual reconciliation with receipts.

Annual income review provisions are essential because the Guidelines contemplate ongoing disclosure obligations. The agreement should specify when income documents must be exchanged (typically in June, after CRA assessments are issued), what documents must be provided, and how the table amount will be adjusted based on updated income figures.

Duration and termination provisions must define when support ends for each child. Under the Divorce Act, a 'child of the marriage' includes a child who has reached the age of majority but remains dependent due to illness, disability, or pursuit of education. The agreement should address post-secondary education specifically, as this is a common area of dispute.

Independent legal advice is strongly recommended for both parents, though not strictly required. A court is more likely to uphold an agreement where both parents received independent legal advice, particularly if the agreement deviates from the Guidelines in any way.