What does it mean to self-assess HST when buying a commercial property in Ontario?
Self-assessing HST means the buyer, rather than the seller, calculates and remits the HST owing on a commercial property purchase directly to the Canada Revenue Agency, instead of paying that tax to the vendor at closing. This mechanism under the federal Excise Tax Act typically applies where the buyer is a GST/HST registrant acquiring the property for use in a commercial activity, rather than as a residential complex.
For many registered buyers, the practical cash impact is minimal: the buyer reports and remits the HST on their own return, then claims an offsetting input tax credit for the same amount if the property will be used in a commercial activity, so no cash may actually change hands with the CRA at all. What matters is getting the mechanics right. If HST is mistakenly paid to the vendor when self-assessment should have applied, or the reverse, it can create a real compliance problem that isn't automatically fixed at closing.
Because whether self-assessment applies depends on both parties' registration status and how the property will be used, buyers should confirm the correct treatment with their lawyer or accountant before closing rather than assuming HST will simply be added to the purchase price.
Key takeaways
- Self-assessment means the buyer remits HST to the CRA directly, instead of paying it to the seller.
- It generally applies when a registered buyer acquires commercial property for a commercial activity.
- A matching input tax credit often offsets the self-assessed amount, minimizing net cash impact.
- Confirm the correct HST mechanics with a professional before closing — errors aren't automatically self-correcting.