Shared Parenting Child Support Rule in Alberta Explained

If your children spend close to half their time with you, you may wonder why support is not simply a matter of who earns more. In Alberta, the shared parenting rule exists for exactly this situation, and it changes how support is worked out.

This article explains where the 40 percent line comes from, what the court looks at once you cross it, and what happens if you fall below it. It is general information, not advice on your own numbers.

This article covers the law of Alberta.

Where the 40 percent rule comes from

The shared parenting rule is section 9 of the Federal Child Support Guidelines. It applies if each parent exercises not less than 40% of parenting time with a child over the course of a year.

Alberta's own guidelines, made under the Family Law Act, adopt the Federal Child Support Guidelines, and the federal tables are used under both the Divorce Act and the Family Law Act. So the approach is the same whether you were married or not.

Which set of rules applies depends on your situation. 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, and 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, while the 2017 tables apply to periods from November 22, 2017 through September 30, 2025.

What the court must consider

Once each parent has at least 40%, the court does not just apply one table amount. It must consider three things:

• The table amounts for each parent, based on each parent's income.
• The increased costs of shared parenting time arrangements.
• The condition, means, needs and other circumstances of each parent and of any child.

Table amounts depend on the paying parent's annual income, the number of children and the payer's province.

Weighing both table amounts and the extra costs

The first factor looks at the table amount for each parent, not only the amount for one of them. The court must consider those table amounts together with the other factors, and how they combine depends on the facts.

The second factor recognizes that running two homes costs more than one. The court must consider the increased costs of shared parenting time arrangements. The third factor lets the court look at each household's real situation, including the needs of the children. How these pieces combine depends on the facts, so a lawyer can help you see how it might apply to you.

Below 40 percent, and other situations

Add-on costs such as child care or medical expenses are dealt with separately under section 7 and are usually shared in proportion to income. The court must also take into account any subsidies, benefits or income tax deductions or credits relating to the expense.

Income, disclosure and special cases

Income drives the table amounts. It is taken from the Total income line of the T1 General tax form, adjusted under Schedule III. When a court application is made, the applicant must include the other parent's personal income tax returns for the three most recent taxation years, plus notices of assessment and reassessment. 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.

Some situations are treated differently:

• If a parent's income in the current year would not fairly reflect their income, the court may look at the last three years.
• For a shareholder, director or officer of a corporation, the court may attribute all or part of the corporation's pre-tax income where the salary figure does not fairly reflect money available for support.
• The court may impute income it considers appropriate, for example for intentional under-employment or unemployment.
• The court may award a different amount if a parent or child would otherwise suffer undue hardship.

What to do next

Existing orders are not automatically changed by the 2025 tables. If the new tables produce a different amount, that may count as a change in circumstances, and parents can seek a variation order or use a recalculation service. After an order is made, and while the child is a child under the Guidelines, a parent must provide updated income documents on written request, not more than once a year, within 30 days (Canada or the United States) or 60 days (elsewhere).

• Keep a calendar or log of actual parenting time across a full year.
• Gather your last three years of tax returns and notices of assessment.
• List the extra costs you carry because of the shared schedule.
• Make a list of child-related add-on expenses and who pays them.
• Speak with a lawyer before signing an agreement that relies on the 40% line.

Frequently asked questions