What happens to a trades business's union agreements if it's sold to a non-union buyer?

Whether a collective agreement continues after the sale depends heavily on the deal structure and, in some cases, on labour relations rules about successor employers. In a share sale, the same corporate employer continues to exist, so the existing collective agreement generally continues to bind it exactly as before; a buyer taking over a unionized shop through a share purchase should assume the union relationship comes with it, not disappears because ownership changed hands.

In an asset sale, the analysis is more complex. Labour relations law recognizes the concept of a "successor employer" in some circumstances, meaning a new owner who continues operating substantially the same unionized business, with substantially the same employees, can end up bound by the existing collective agreement even though it's technically a new legal entity — this isn't automatic in every asset sale, and depends heavily on the specific facts of how much of the business, and which employees, actually continue.

Because getting this wrong can mean either an unwelcome surprise (being bound by a collective agreement you didn't expect) or a labour relations complaint (treating employees as though the union relationship ended when it legally didn't), this is worth specific legal review before assuming either outcome in a unionized trades business sale.