Will I be responsible for the previous owner's debts if I buy a business in Ontario?

It depends on whether you buy shares or assets. In a share purchase, the corporation's WSIB account, including any amounts owing, stays with the corporation, so you take the company as it is. In an asset purchase, some statutory debts can still follow the business.

For WSIB, a buyer of all or part of a business is liable for amounts the employer owed immediately before the sale. Without a valid purchase certificate, the WSIB may hold you liable for what the seller owed up to the date of sale. For tax, you can be jointly liable for the seller's tax debts when property comes from a spouse, common-law partner, person under 18 or non-arm's-length person, up to a cap. For GST/HST, transfers between separated spouses or common-law partners under a court order, judgment or written separation agreement are treated as having a fair market value of nil.

Creditors with security are a separate risk. Buying assets outside the ordinary course does not give you the protection an ordinary-course buyer gets, so a PPSR search and lien discharges matter. Holdbacks and indemnities are negotiated in the agreement, so their terms depend on the deal, and a lawyer can review them before you sign.