Retroactive Child Support and Arrears in Canada

Reviewed October 3, 2026 · 4 min read · Sources

Two different things: retroactive support and arrears

Arrears are payments that an order or agreement required and that were not made. They are a debt. Retroactive support is different. It covers a time when there was no order, or when the order was based on an income that had since gone up.

How far back a court will go

The Supreme Court of Canada set the framework in D.B.S. v. S.R.G. (2006). A court weighs four things:

1. Whether the parent asking had a reasonable excuse for not asking sooner.
2. The conduct of the paying parent, such as hiding a raise.
3. The circumstances of the child, then and now.
4. Any hardship a retroactive award would cause.

As a general rule the award goes back to the date of effective notice. That is the date the receiving parent first raised the subject of support or of an increase. It does not have to be a court filing. The court will generally not go back more than three years before formal notice, unless the paying parent engaged in blameworthy conduct. Then the award can go back to the date the income actually changed.

A worked example

A parent in Ontario pays $556 a month for one child, based on a $60,000 income. In January 2024 their income rises to $85,000 and they do not tell the other parent. The other parent finds out and applies in September 2026.

• January 2024 to September 2025 is 21 months under the 2017 table. The table amount on $85,000 was $792, which is $236 a month more than was paid.
• October 2025 to September 2026 is 12 months under the 2025 table. The table amount on $85,000 is $792, which is $236 a month more than the $556 still being paid.
• The shortfall is 21 × $236 plus 12 × $236, or about $7,788.

Work out your own figure with the back support calculator. It uses the 2017 table for months before October 2025 and the 2025 table after.

After the child has grown up

In Michel v. Graydon (2020), the Supreme Court allowed a retroactive increase under British Columbia’s Family Law Act even though the child was already an adult and the order had ended. The father had understated his income. Under the Divorce Act, a first application for support generally has to be made while the child still qualifies, so timing matters. Get advice quickly if your child is close to finishing school.

When the paying parent asks to reduce arrears

Colucci v. Colucci (2021) deals with the other direction. A paying parent whose income dropped can ask to lower support for the past, but only back to the date they gave the other parent real notice with supporting documents, and generally no more than three years before the formal application. Saying nothing and letting arrears build is the worst option. In that case the Supreme Court refused to cancel about $170,000 in arrears.

Is there a time limit to collect arrears?

Limitation periods come from provincial law. In Ontario there is no limitation period for enforcing a court order. In British Columbia, the Limitation Act does not apply to arrears of child support under a judgment or a filed agreement. In Alberta, the Maintenance Enforcement Act says the right to enforce maintenance arrears is not limited by the Limitations Act. How arrears are collected.

Common questions

General information only, not legal advice. For your situation, speak with a family lawyer or your province's family justice services.