How is HST handled differently when I buy a commercial building instead of a home in Ontario?

Buying a commercial building triggers HST in a different way than buying a home does. Most resale homes are exempt from HST because they're "used residential complexes," and only new or substantially renovated homes attract the tax. Commercial real property works the other way around: a sale by a GST/HST registrant in the course of a commercial activity is generally taxable under the federal Excise Tax Act, whether the building is brand new or has been used for decades. Age isn't the dividing line the way it is for houses.

There's also a mechanical difference in how the tax moves. On many commercial deals between registered businesses, the buyer doesn't pay HST to the seller at closing at all — instead, the buyer self-assesses and remits the tax directly to the Canada Revenue Agency, then typically claims an offsetting input tax credit if the property will be used in a commercial activity. Getting this wrong can create real cash-flow and compliance headaches.

Because the correct treatment depends on both parties' registration status and intended use, confirm it with a lawyer or accountant before closing rather than assuming it works like a home purchase.