Do common-law partners owe child support in Ontario after a short relationship?

The length of a common-law relationship does not determine whether a parent owes child support. The obligation to support a child arises from parentage, not from the duration of the relationship with the other parent. A person who is a legal parent of a child — whether the relationship lasted two months or twenty years — owes support for that child under Ontario law.

Common-law relationship length does become relevant for spousal support, where the duration and nature of the relationship affect entitlement. But child support is entirely separate from spousal support. As long as parentage is established — through birth registration, acknowledgment, or a court order — the parent owes support under the Child Support Guidelines regardless of how briefly they lived with or knew the other parent.

If parentage is in dispute (for example, the alleged payor denies being the child's parent), the issue must be resolved before support can be set. A court can order a DNA test to establish or rule out parentage. Once parentage is confirmed, the Guidelines apply in the same way they would for any other Ontario case. A lawyer can advise you on parentage proceedings and the steps to establish or respond to a child support claim in a short-relationship context.