Can a collective agreement's grievance procedure bind me even though I never negotiated it?

Yes, this can happen, and it surprises buyers who assume that because they never sat at the bargaining table, an existing collective agreement's procedures can't apply to them. If Ontario labour relations law's successor-rights provisions apply to your transaction — generally because you're continuing substantially the same unionized business — you can be treated as stepping into the seller's position as employer under that collective agreement, including its grievance procedure, arbitration provisions, and other negotiated terms, exactly as if you had negotiated them yourself.

This isn't limited to grievances that already existed before you bought the business; it can extend to how future disputes with the unionized workforce are required to be handled going forward, for as long as the agreement remains in force or until it's renegotiated through the normal collective bargaining process.

Whether this applies depends on the substance of your transaction, assessed by a labour relations board if it's disputed, not on whether you personally agreed to the terms. Get this evaluated before closing if any part of the business is unionized. A Treadstone business lawyer can help assess your likely exposure.