Can I be on the hook for a seller's unpaid HST even in an asset deal?

Generally, no — an asset purchase is deliberately structured so the buyer only takes on the liabilities the purchase agreement says it's taking on, and unpaid HST is ordinarily left as a debt of the selling corporation rather than something assumed by the buyer. That structural protection is one of the main reasons buyers favour asset deals when a seller's financial history looks anything less than pristine.

The nuance is that this protection is only as good as how the deal is actually documented and closed. If the agreement is vague about which liabilities transfer, if sale proceeds aren't properly directed to clear known tax debts at closing, or if you continue operating under circumstances a court could later characterize as a continuation of the same business rather than a genuine arm's-length asset purchase, exposure can creep back in. There's also a separate question, unrelated to the seller's debts, of whether GST/HST applies to the sale of the assets themselves — that's a transaction-level tax issue, not the same as inheriting the seller's outstanding remittances.

Clear liability language, proper payout direction at closing, and confirming the seller's HST account is current are the practical safeguards. A Treadstone business lawyer can build these into your closing documents.