Generally, GST/HST registrants have to collect the GST/HST on all taxable (other than zero-rated) supplies of goods and services they provide to their customers. You do not charge GST/HST on these zero-rated supplies. But you may claim ITC on these purchases.
Exempt supplies – are supplies of property and services that are not subject to the GST/HST. GST/HST registrants cannot claim input tax credits to recover the GST/HST paid or payable on expenses related to making exempt supplies. But public service bodies can get rebate for GST/HST they paid related to making the exempt supplies.
You do not have to register GST/HST if:
• you are a small supplier (that does not carry on a taxi business);
• your only commercial activity is the sale of real property, other than in the course of a business. Although you do not have to register for the GST/HST in this case, your sale of real property may still be taxable and you may have to charge and collect the tax. For more information, see Real property; or
• you are a non-resident who does not carry on business in Canada.
• a sole proprietor or partnership or a corporation and your total revenues from taxable supplies (before expenses) are $30,000 or less in any single calendar quarter and in the last four consecutive calendar quarters; A public service body (charity, non-profit organization, municipality, university, public college, school authority, or hospital authority) is defined of $50,000. A gross revenue threshold of $250,000 also applies to charities and public institutions. See Guide RC4082, GST/HST Information for Charities.
Please note if you choose not to register, you do not charge the GST/HST (other than on certain taxable supplies of real property), and you cannot claim ITCs.
Determining the effective date of registration for small supplier, please see