Can I register a writ of seizure and sale against land I own jointly with someone else in Ontario?

A judgment creditor can generally register a writ of seizure and sale against real property even where the judgment debtor owns it jointly with someone else, since the writ attaches to whatever interest the debtor actually has in the land, not to the property as a whole. This means a co-owner who has nothing to do with the debt doesn't lose their own share, but the debtor's interest in the property becomes encumbered and can complicate any future sale or refinancing of the whole property until the debt is dealt with.

Actually forcing a sale of jointly owned property to satisfy one owner's debt is more involved than seizing property owned outright by the debtor alone, since a court generally needs to weigh the innocent co-owner's interest before ordering a sale that would affect them too. In practice, a creditor holding a writ against a co-owned property often has real practical leverage even without forcing an immediate sale, since the encumbrance can make it difficult for the debtor, or the co-owners together, to sell or refinance cleanly. Co-owners dealing with this situation are often better served working out a resolution directly with the creditor than waiting for a forced sale process to unfold.