Is It Illegal Not to Tell the CRA You Are Common-Law in Ontario?

Ignoring your common-law status is risky, because the rules require you to report it. You must tell the CRA about a change in marital status by the end of the month after the change. Whether you are common-law is decided by the definition, not by how you file. The CRA defines living common-law as a conjugal relationship with a person who is not your married spouse, where the person has lived with you for at least 12 continuous months, is the parent of your child by birth or adoption, or has custody and control of your child who is wholly dependent on them.

A short separation does not necessarily change your status. Couples are deemed to keep cohabiting unless they live separate and apart for at least 90 days because of a breakdown of the relationship. A separation counts for reporting once it has lasted more than 90 days because of a breakdown in the relationship.

The penalties, interest and any effect on benefits or credits you received depend on your situation. If you think you filed as single when you were common-law, speak with an accountant or the CRA about correcting past returns.