When do you have to register for a GST/HST number?

The test looks at your worldwide taxable revenues — the gross amount you bill for taxable goods and services, before expenses. It is measured over four consecutive calendar quarters, not your fiscal year, and it includes revenue from associated businesses.

Zero-rated supplies count toward the threshold. Exempt supplies do not. If you are unsure which category your work falls into, confirm it with your accountant before assuming you are under the line.

• Over $30,000 in one quarter: you stop being a small supplier immediately, and the supply that pushed you over is taxable
• Over $30,000 across four quarters: you cease to be a small supplier at the end of the month following that quarter, and must register by the end of the month after that
• Taxi and ride-share drivers: must register regardless of revenue

Registering voluntarily means charging GST/HST from day one and filing returns, but it also lets you recover the tax you pay on materials, tools, vehicles and software through input tax credits. For trades and contractors with real material costs, that recovery often outweighs the paperwork.

If most of your customers are themselves registered businesses, the tax you charge is neutral to them — they claim it back — so early registration rarely costs you work.

Store your GST/HST number once and it appears on every invoice automatically, in the format the CRA expects. Until you are registered, you can invoice without tax lines, and the compliance checks will tell you what is missing before you send.

Provincial registrations for QST, PST and RST are stored separately, because they follow different rules and different thresholds.

What is the small supplier threshold?

If your worldwide taxable revenues are $30,000 or less over four consecutive calendar quarters, you can generally stay a small supplier and are not required to register for GST/HST.

What happens the moment I go over $30,000?

If you exceed the threshold in a single calendar quarter, you stop being a small supplier immediately and must charge GST/HST on the supply that put you over. If you exceed it across four consecutive quarters, you cease to be a small supplier at the end of the following month.

Can I register before I hit the threshold?

Yes. Voluntary registration lets you claim input tax credits on business purchases, which often makes sense if you buy materials, tools or software. The trade-off is filing returns and charging tax to customers.

Can I charge GST/HST before I have a number?

No. You need a GST/HST registration number and it must appear on invoices for taxable supplies. Charging tax without a valid number is a problem for you and for your customer's claim.