Shared Parenting Time and Child Support in BC: The 40 Percent Rule

If your child spends substantial time with both parents, the usual table amount may not tell the whole story. The 40 percent rule is where that difference starts.

This article explains how the rule works in British Columbia, what set-off means in plain terms, and what other factors can change the result.

This article covers the law of British Columbia.

The usual starting point: the table amount

Child support orders under the Family Law Act must follow the child support guidelines, and under the Divorce Act a court must make an order in accordance with the applicable guidelines. The presumptive amount is the table amount for the payor's province plus any section 7 expense amount.

The table uses the payor's income only. Monthly support is a basic amount for the income row plus a percentage of income over the row's floor. For example, in the current BC table, one child at the $50,000 row is $468 plus 0.94% of income over $50,000. For two children at the $75,000 row, it is $1,166 plus 1.58% of income over $75,000. Look up your exact row in the official table.

The Guidelines were last amended on 2025-10-01, which is when the current table figures took effect, and earlier versions had lower amounts. A parent's annual income is generally determined from the Total income heading of the T1 General tax form, adjusted under Schedule III, and a court may look at the last three years where income fluctuates.

What the 40 percent rule says

If each parent exercises not less than 40% of parenting time with a child over the course of a year, the court must consider the table amount for each parent (set-off), the increased costs of shared arrangements, and each parent's circumstances.

Set-off means working out what each parent would pay under the table and comparing the two amounts. It is one of three things the court looks at, not an automatic subtraction.

• The table amount for each parent.
• The increased costs of shared arrangements.
• Each parent's circumstances.

Because the measure is a full year, a schedule on paper and the time a child actually spends with each parent can differ. It helps to know which one applies to your family before you rely on any estimate.

Related situations that work differently

Section 7 expenses such as child care or medical costs can still be requested and are shared in proportion to incomes. For school and extracurricular costs, only expenses that are extraordinary, meaning they exceed what the requesting parent can reasonably cover, are added.

Agreements and departures

The Family Law Act lets a court depart from the guidelines if the parties consent or have an agreement and reasonable arrangements exist for the child's support. Arrangements are not unreasonable merely because they differ from the guideline amount. However, parents cannot agree that support is not payable at all.

Support and parenting time are separate. A paying parent cannot withhold support over parenting time issues, and a parent cannot refuse parenting time because support is behind.

An existing order does not end or change on its own. A court may change, suspend or terminate a child support order on application. How this applies to a shared schedule that changes over time depends on your situation, so it is worth confirming with a lawyer.

What to do next

• Track actual parenting time across a full year, not just what the schedule says.
• Gather both parents' income tax returns, since disclosure of recent returns is required.
• List extra costs of running two households for the child.
• Look up the table amount for each parent's income.
• Speak with a lawyer before signing an agreement based on a shared schedule.

If support is unpaid and you have a written agreement or order, you can enrol it with the BC Family Maintenance Agency, which can enforce it if necessary. An agreement must first be filed with the court registry to be enrolled.

Frequently asked questions