If you're self-employed, freelancing, or running a small business in Canada, one of the first tax questions you'll run into is whether you need to charge GST or HST on what you sell. The answer usually comes down to one number: $30,000.
The $30,000 small-supplier threshold
Most businesses and self-employed people in Canada must register for a GST/HST account once their total worldwide taxable revenue — including that of any associated businesses — goes over $30,000 across four consecutive calendar quarters, or within a single calendar quarter. This is the Canada Revenue Agency's (CRA) "small-supplier" threshold. Below it, registration is optional; above it, it's mandatory.
A few things to note about how that threshold is measured: it's based on gross revenue before expenses, not profit, and it's cumulative over a rolling four-quarter window rather than a single calendar year. It's possible to cross the threshold partway through a year, in which case you generally need to start charging tax as of the transaction that puts you over the limit.
Why some businesses register early anyway
Registration below $30,000 is optional, but some small businesses choose to register voluntarily even before they're required to. The main reason is input tax credits: once registered, a business can claim back the GST/HST it pays on its own business expenses — equipment, supplies, software, professional fees — which can be worth doing even at a smaller revenue scale, especially for businesses with significant upfront costs.
What changes once you're registered
Once you have a GST/HST number, you're required to:
- Charge GST/HST on your taxable sales, at the rate that applies where the customer takes possession of the goods or service — not necessarily your own province's rate
- File returns on your assigned schedule (monthly, quarterly, or annually, depending on your revenue)
- Remit what you collect, minus any input tax credits, to the CRA
That means a registered business in a GST-only province like Alberta still needs to charge 13% HST on a sale shipped to a customer in Ontario — the rate follows the customer, not the seller's home province. See our GST calculator and HST calculator for the specific rates involved.
How the threshold is tracked
The CRA looks at your total taxable revenue on a rolling basis: the most recent four consecutive calendar quarters, plus a check on any single quarter on its own. If either measure crosses $30,000, you're no longer considered a small supplier as of that point and generally need to register. This is different from waiting until the end of a calendar year or a fiscal year — it's possible to cross the threshold mid-year, and the registration requirement kicks in from the point of the sale that puts you over the line, not from the start of the next tax year.
This isn't tax advice
The $30,000 threshold and the registration process have specific rules for edge cases — associated businesses, non-resident sellers, and particular industries can all work differently. If you're close to the threshold, unsure whether to register early, or dealing with sales across multiple provinces, it's worth talking to a Canadian accountant or contacting the CRA's GST/HST enquiries line directly rather than relying on a general explainer like this one.
Working out what to charge
Once you know you need to charge tax, the next question is usually how much. Our homepage calculator covers all 13 provinces and territories with current 2026 rates, and if you need to work backwards from a tax-included total a client has already paid, the reverse sales tax calculator splits that back into the subtotal and tax portions automatically.