For buyers, HST (GST+PST) owed on the purchase price of non-exempt property, as well as fees and commissions for professional services, is paid at closing.
For sellers, HST (GST+PST) owed on fees and commissions for professional services is also paid at closing.
Your REALTOR can answer your questions about the closing date and HST (GST+PST) payments. For additional HST (GST+PST) information, contact your local Revenue Canada Tax Services Office.

Whether you're buying or selling a home, the Goods and Services Tax, or HST (GST+PST), will probably apply to the transaction. However, with HST (GST+PST) rebates and exemptions, figuring out its impact on your transaction can be confusing. Real estate professionals are familiar with this tax and can help you understand how it works.
You must be sure that the HST does not apply, please read about New rules with the HST, please check the Ontario government HST websites