Split Custody Child Support in Alberta: When Each Parent Has Different Children

Some families do not divide neatly. After a separation, one child may live mostly with one parent and another child mostly with the other. People often call this split custody. The Guidelines call it split parenting, and they have a specific method for it.

This article explains how that method works in Alberta, how it differs from shared parenting, which law applies to you, and what income information each parent must provide. It does not give dollar amounts, because those come from the official tables and depend on your own income and situation.

This article covers the law of Alberta.

What split parenting means and how the set-off works

Split parenting applies where each spouse has the majority of parenting time with different children. In that case, the amount is the difference between the amounts each spouse would otherwise pay under the applicable tables.

In plain words, this is a set-off. Each parent is treated as a payer for the child or children living mostly with the other parent. The two amounts are compared, and only the difference is paid. The parent with the higher resulting amount pays the other parent.

• Step one: work out what Parent A would pay for the child or children living mainly with Parent B.
• Step two: work out what Parent B would pay for the child or children living mainly with Parent A.
• Step three: subtract the smaller figure from the larger one. That difference is the amount paid.

What goes into each parent's table amount

Table amounts are driven by the paying parent's annual income, the number of children, and the province of the payer. Income is taken from the Total income line of the T1 General tax form, adjusted under Schedule III. The applicable table is generally the one for the province where the paying spouse habitually resides when the application is made, with exceptions where the payer's residence changes or is outside Canada.

In a split arrangement, each parent's calculation uses that parent's own income and the number of children living with the other parent. The court can also look beyond the plain tax-return figure in some cases. For example, it may consider the last three years of income if the current year does not fairly reflect a spouse's income, or impute income where there is intentional under-employment.

Where a paying spouse's income is over $150,000, the court may depart from the plain table amount. A lawyer can tell you how these rules might apply to your income.

How this differs from the 40% shared-parenting rule

Split parenting and shared parenting are often confused, but they are different rules. Shared parenting under s. 9 applies when each spouse exercises not less than 40% of parenting time with a child over the course of a year. Split parenting is about which parent has the majority of time with each different child.

Below the 40% threshold, the shared-parenting analysis does not apply and the ordinary table amount for the paying parent is used, subject to hardship and to the rule for income over $150,000. Families with more than two children, or with a mix of arrangements, should get advice on which rules combine.

Special expenses and which law applies

Special or extraordinary expenses under s. 7 can still be claimed. These can include child care, health-related expenses over a threshold, extraordinary school or extracurricular costs, and post-secondary education. The guiding principle is that these expenses are shared in proportion to the spouses' incomes, after deducting any contribution from the child. The court must also take into account any subsidies, benefits, or tax deductions or credits relating to the expense.

Which law applies depends on your relationship. Divorcing spouses are under the Divorce Act, and the Federal Child Support Guidelines apply unless both spouses are habitually resident in a province designated by order. Unmarried, separated-but-not-divorced, and adult interdependent partners proceed under Alberta's Family Law Act and the Alberta Child Support Guidelines. The Alberta guidelines adopt the Federal Child Support Guidelines in Schedule 1, so the table amounts are the same.

Updated Federal Child Support Tables took effect October 1, 2025. In Alberta, the 2025 tables apply to periods on or after October 1, 2025, and the earlier tables apply to periods from November 22, 2017 through September 30, 2025. Existing orders are not automatically changed by the new tables.

Disclosure: sharing income information

Because both parents' incomes drive the calculation in a split arrangement, accurate income information matters on both sides. When an application is made, it must include a copy of every personal income tax return filed by the spouse for each of the three most recent taxation years, plus notices of assessment and reassessment, and pay information if the spouse is an employee.

A respondent served with an application must provide the same income documents within 30 days if in Canada or the United States, or 60 days if elsewhere, unless the court sets another deadline. If a spouse does not comply, the other spouse may apply for a hearing or judgment, or for an order requiring the documents, and the court may also impute income.

Disclosure continues after an order is made. A spouse must provide updated income documents on written request, not more than once a year, within 30 days in Canada or the US, or 60 days elsewhere.

What to do next

• Write down which child lives mainly with which parent, and roughly how parenting time is divided over a year.
• Gather your last three years of tax returns and notices of assessment.
• List any child care, medical, school, activity or post-secondary costs you want shared.
• Confirm whether you are divorcing or unmarried, since that decides which law applies.
• If you have an existing order, ask a lawyer whether the 2025 tables might change the amount and whether to seek a variation.
• Get legal advice before signing an agreement, so the terms can be enforced if needed.

Frequently asked questions