When do you have to register for HST in Ontario? The $30,000 small supplier rule

Who is a small supplier?

According to CRA's registration page, you are a small supplier if your total revenue from taxable supplies (worldwide, including those of your associates) is $30,000 or less in a single calendar quarter and over the last four consecutive calendar quarters. Small suppliers do not have to register, but they can register voluntarily. Some businesses, including taxi and commercial ride-sharing drivers, must register even if they are small suppliers.

Test 1: you exceed $30,000 in a single calendar quarter

If you go over $30,000 in one calendar quarter, you stop being a small supplier with the sale that pushes you over. You must charge HST on that sale and every taxable sale after it, and register within 29 days of that sale.

Test 2: you exceed $30,000 over four consecutive quarters

If no single quarter goes over $30,000 but the last four calendar quarters add up to more than $30,000, you stay a small supplier until the end of the month after the quarter in which you went over. You start charging HST on the first taxable sale after that, and register within 29 days of that sale.

Worked example

An Ontario freelance photographer starts in January 2026 and earns the following taxable revenue:

No single quarter crossed $30,000, so test 2 applies. The photographer went over in the October–December 2026 quarter, so they remain a small supplier until the end of the following month, January 31, 2027. They start charging 13% HST on their first taxable sale after that date and must register within 29 days of it.

Now suppose instead that a $35,000 contract was billed in a single quarter. Test 1 applies: the photographer must charge HST on that contract itself, because that is the sale that put them over.

Voluntary registration

You can register before you are required to. Registering lets you claim input tax credits on start-up costs, and some business clients expect suppliers to be registered. The trade-off is that you must charge HST on your taxable sales and file returns. CRA says a voluntary registration can generally be backdated up to 30 days before the date of your request, and you may have to stay registered for at least one year.

For Ontario trades getting close to $30,000, a missed call can be a missed job. CallCatch has a free missed-call text template you can send back to callers.

Once you are registered and have a year of business behind you, the Quick Method may lower what you remit. Small businesses that register early may also qualify right away: a new registrant can elect if it reasonably expects $400,000 or less of taxable supplies in its first full year.