You must register for GST/HST once your worldwide taxable revenue passes $30,000, measured either in a single calendar quarter or over four consecutive calendar quarters. That is gross revenue, before you take off any expenses, and it counts across all your business activities combined. Below $30,000 you are a "small supplier" and registration is optional. The figure that trips people up is not the threshold itself but the timing rule, and there are two different ones depending on how you cross.
The $30,000 small-supplier threshold
The $30,000 is cumulative and applies to all your business activities and trade names together. You cannot split revenue between two trading names to keep each one under $30,000. It is gross, so a tradesperson billing $32,000 with $12,000 of materials costs has still crossed the threshold; the test is revenue, not profit.
The two timing rules (the 29-day rule)
How and when you register depends on how you cross the line:
- You exceed $30,000 in a single calendar quarter. You stop being a small supplier immediately. You must register straight away and start charging GST/HST on the very supply that pushed you over, and on everything after it.
- You exceed $30,000 over four consecutive calendar quarters (but no single quarter on its own). You stop being a small supplier at the end of the month following the quarter in which you crossed. You then have to register within 29 days of the day you became liable. Charge GST/HST from your effective date of registration.
If you are unsure which case applies, register as soon as you can see $30,000 coming. Charging late is harder to fix than charging early.
Voluntary registration below $30,000
You can register voluntarily before you hit the threshold. The main reason a new trade business does is Input Tax Credits (ITCs). Once registered, you claim back the GST/HST you paid on business spending: tools, materials, a work vehicle, equipment. For a startup buying a lot of kit, voluntary registration can produce a real refund in year one.
The trade-off: once registered, you must charge GST/HST on all your taxable supplies, file returns every reporting period (even a nil return), and keep your records for six years. You cannot easily de-register again in the short term. Voluntary registration suits you if your startup spending is heavy or you are already close to $30,000; it adds admin you do not yet need if you are nowhere near.
Picking a reporting period
When you register, you choose (or are assigned) a reporting period: annual, quarterly or monthly. Smaller businesses usually default to annual filing, which means less paperwork but a single larger payment. Quarterly filing spreads the remittance and the record-keeping across the year, which many tradespeople find easier to manage for cash flow. You can often elect a more frequent period than the default if it suits you. Whatever you pick, file on time: even a nil return must be filed, and missed returns hold up your compliance standing.
The rate map: charge by place of supply
You charge the rate of the province where the work is done, not where you are based. The combined rates are:
- Alberta, Northwest Territories, Nunavut, Yukon: 5% (GST only, no provincial sales tax)
- British Columbia: 12% (5% GST plus 7% PST; PST applies to materials, labour is often exempt)
- Manitoba: 12% (5% GST plus 7% RST)
- Saskatchewan: 11% (5% GST plus 6% PST)
- Ontario: 13% HST
- Nova Scotia: 14% HST (reduced from 15% on April 1, 2025)
- New Brunswick, Newfoundland and Labrador, Prince Edward Island: 15% HST
- Quebec: 14.975% (5% GST plus 9.975% QST)
In the participating provinces (Ontario, New Brunswick, Nova Scotia, Newfoundland and Labrador, Prince Edward Island) the HST is a single tax you register for once with the CRA. In British Columbia, Saskatchewan and Manitoba the provincial sales tax is run by the province, not the CRA, so you register for GST with the CRA and for the provincial tax separately with the province.
Quebec is its own system
If you do work in Quebec you need two registrations. The CRA administers GST; Revenu Quebec administers the Quebec Sales Tax (QST) separately. Register for QST through the Revenu Quebec portal at revenuquebec.ca (a business based outside Quebec uses Form LM-1-V). Charging only GST on Quebec work, and forgetting the QST, is a common and expensive error.
A note on new housing
New residential construction can carry GST/HST rebates, such as the GST/HST New Housing Rebate, but those are claimed by the owner or buyer, not you. As the contractor you charge the full applicable HST; the client applies for any rebate. Misapplied tax treatment on new builds is a common audit trigger, so get the rebate rules straight before you quote a new build.
Common mistakes
- Splitting trade names to stay small. The $30,000 is across all your activities. Two names do not buy you two thresholds.
- Testing on profit, not revenue. The threshold is gross revenue. Materials-heavy jobs still count in full.
- Missing the 29-day window. When you cross over four quarters, you have 29 days from becoming liable to register.
- Forgetting Quebec's QST. Work in Quebec needs a separate Revenu Quebec registration on top of GST.
- Not filing nil returns. Once registered, every period needs a return, even a zero one.
Common questions
Do I have to charge GST/HST from day one?
No. While your worldwide taxable revenue stays under $30,000 over four consecutive calendar quarters you are a small supplier and registration is optional. You must register once you cross $30,000, and you have 29 days from the day you exceed it to register and start charging.
Should I register before I hit $30,000?
Often yes. Registering voluntarily lets you claim input tax credits on your startup costs (tools, van, materials), which you cannot do as an unregistered small supplier. The trade-off is the paperwork of filing returns.
Which rate do I charge?
The rate follows the province where the supply takes place, not where your business is based. It ranges from 5 percent GST in Alberta and the territories to 13 to 15 percent HST in the participating provinces. Charge the rate for the customer's province.
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Keep reading
Need help pricing your work? Read Section 14: Pricing Your Work - day rates, job prices and how to stop underselling yourself.
Finished your apprenticeship? Read our guide: After Your Apprenticeship - the stuff nobody teaches you in college.
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