What is the difference between a separation agreement and a cohabitation agreement in Ontario?

Both are domestic contracts under Ontario's Family Law Act, but they are used at different stages and for different purposes. A cohabitation agreement is made before or during a common-law relationship to set out property and support rules while the couple is together (or in the event they separate). A separation agreement is made after a couple has separated and is used to resolve the practical and legal consequences of the breakup.

A separation agreement deals with what has already happened: it divides the couple's property, addresses support, and sets out parenting arrangements if there are children. It is the legal document that closes out the financial and family relationship between the partners. For married couples, a separation agreement does not end the marriage itself — a court order (divorce judgment) is needed for that — but it can resolve all other issues.

A cohabitation agreement is forward-looking and preventive. It is designed to avoid disputes; a separation agreement is designed to resolve them. Ideally, a separation agreement simply implements the framework the parties already agreed to in their cohabitation or marriage contract, making the process faster and less expensive. Where no prior agreement exists, the separation agreement must be negotiated from scratch, often with more conflict.