Small supplier threshold Canada: when you must register for GST/HST

For a while, a small Canadian business can stay out of the GST/HST system. Then a line is crossed and registration is no longer optional. The trigger is not a single good month — it is a rolling year of revenue.

What the small supplier threshold is

The phrase describes a level of taxable revenue below which you are not required to register for GST/HST. It is not a registration you opt into; it is a ceiling, and it applies to your taxable supplies over a defined period.

The specific figure is not fixed forever, and it is not the only variable. What counts as a taxable supply, and which period is measured, both matter as much as the number. Confirm the current figure and the rules for your situation on the CRA's GST/HST pages, or with an accountant, rather than working from a number you remember.

Four consecutive quarters, not a calendar year

The measurement that matters for many small businesses is your taxable revenue over four consecutive calendar quarters. That window does not have to line up with your tax year or anyone's fiscal year. It moves.

The practical effect is that you can cross the line partway through a year, not only at December 31. Once your rolling four-quarter total goes past the threshold, you generally have a short window from the end of the quarter in which you crossed it to register. The window is narrow and easy to miss, so watch the total as it moves rather than checking at year end.

Registering voluntarily

Below the threshold, you can register voluntarily. That is a real choice with real consequences, not just paperwork.

On the plus side, registering lets you claim input tax credits — the tax you paid on business purchases comes back. If your customers are other businesses, they expect to see tax on your invoice anyway, and registering stops you losing that tax out of your own margin.

On the other side, registering means charging tax, filing returns, and keeping the records to support them. If most of your customers are consumers who cannot reclaim the tax, you may be adding an amount they will feel, or absorbing the difference in your price. Whether voluntary registration helps depends on who you sell to and how much tax you pay on the way in.

What changes on your invoices

This is the change a client notices first:

• GST/HST now appears as a separate amount on the invoice.
• Your GST/HST registration number goes on the invoice, so a business client can claim the tax back.
• The tax you collected is not your revenue — it is held for the CRA until you remit it.
• From the effective date, you file returns on the schedule you agreed to — often quarterly or annually.

The date matters. Tax applies from the effective date of registration forward. Do not charge GST/HST on invoices you issued before that date, and do not skip it on invoices after — the two get mixed up when the switch happens mid-quarter.

The records behind the decision

Knowing whether you are near the threshold depends on a running total of your taxable sales, quarter by quarter. In a folder of bank statements that total is invisible; on a single sheet it is a number you can watch. As it approaches the line, that same set of records is what tells you what you have to remit once you are registered. Build the habit of logging sales as they happen, and the four-quarter total is always current rather than a scramble at the end of a quarter.