Rules checked: October 24, 2026, against the Canada Revenue Agency’s guidance on canada.ca. This is general information, not legal or tax advice. Talk to an accountant about your own situation.
Disclosure: TradesTally is written by Kris, who owns VB Concrete & ICF Structures, an Ontario concrete and ICF contractor. TradesTally may earn commissions from some links in the future. There are no affiliate links in this article.
Almost every new trade business hears the same thing: “You don’t need to charge HST until you hit $30,000.” That’s roughly right, but the details matter, and getting them wrong can mean owing HST you never collected.
For a contractor the risk is real. One mid-sized job, like a foundation, a roof or a basement finish, can push you over the line in a single quarter. This guide walks through how the Canada Revenue Agency (CRA) actually applies the small supplier rule, using CRA’s own wording.
The basic rule: who has to register
CRA says you must register for the GST/HST if both of these are true:
- you make taxable supplies in Canada, and
- you are not a small supplier.
(Canada.ca: When to register for and start charging the GST/HST)
Construction and renovation work is a taxable supply, so for most trade businesses the question is simply: are you still a small supplier?
What counts as a “small supplier”
CRA says you are a small supplier if “your total revenues from taxable supplies (before expenses) from all your businesses are $30,000 or less over the last four consecutive calendar quarters or in a single calendar quarter.” (Canada.ca)
Three parts of that sentence matter most to contractors.
1. It’s revenue, not profit
The $30,000 is measured before expenses. If you invoiced $34,000 over four quarters but spent $20,000 on concrete, lumber, rentals and fuel, you’re not “at $14,000.” For this test you’re at $34,000, and you’re over.
Materials-heavy trades hit the threshold much sooner than their take-home pay suggests.
2. It’s all your businesses, and your associates
CRA’s wording covers revenue “from all your businesses.” CRA also says the total includes taxable supplies made by you and your associates, worldwide. (Canada.ca) Whether another business counts as an “associate” depends on ownership and control rules that are beyond this article. If you or your family own more than one company, ask your accountant how the association rules apply.
3. It’s four calendar quarters, not your fiscal year
The test looks at the last four consecutive calendar quarters: January–March, April–June, July–September, October–December. It isn’t based on your fiscal year-end or on a January-to-December year. It’s a rolling window you need to check every quarter.
The two ways you stop being a small supplier
CRA treats the two situations differently, and the difference matters a lot.
Scenario A: you go over $30,000 across four quarters
If your taxable revenues go over $30,000 over four consecutive calendar quarters (without going over in any single quarter), CRA says you’re no longer a small supplier “at the end of the month after the quarter” in which you went over. CRA adds that you’re considered a small supplier up to that day. (Canada.ca)
That gives you a short runway: you keep your small-supplier status through the end of the following month, then you must start charging HST.
Example (illustrative numbers): a renovator bills $6,000, $8,000, $7,000 and $10,000 across four consecutive calendar quarters, ending with the July–September quarter. That’s $31,000, which is over $30,000, but no single quarter is over $30,000. Under CRA’s rule, they stop being a small supplier at the end of the month after that quarter (the end of October).
Scenario B: you go over $30,000 in a single quarter
This is the trap. If you go over $30,000 in a single calendar quarter, CRA says you are not a small supplier anymore, and “you have to charge the GST/HST on the supply that made you go over the threshold.” (Canada.ca)
There’s no grace month. The invoice that pushes you over the line is itself taxable.
Example (illustrative numbers): a new concrete sub has billed $12,000 this quarter, then lands a $25,000 garage slab in the same quarter. That’s $37,000 in one quarter. Under CRA’s rule, the HST applies to the $25,000 slab invoice, the supply that crossed the threshold.
If you priced that job without HST and invoiced it that way, the tax may effectively come out of your margin. For a trade business, that’s the single most common way the small supplier rule causes real damage.
Deadlines once you’re over
Registering
CRA says that once you’re no longer a small supplier, “you have to register within 29 days of the day you made the supply that made you go over the threshold.” (Canada.ca)
In practice: if you can see a big job coming that will take you over, register before you send the invoice, so the invoice can carry your GST/HST number and the right tax.
Your effective date
Your effective date of registration is the date from which you must charge, collect and remit HST. CRA’s guidance explains how it’s set depending on which scenario applies. Use CRA’s page and your accountant to get it right, because it decides which invoices are taxable.
Voluntary registration: registering before you have to
You don’t have to wait until you cross $30,000. Small suppliers can register voluntarily. CRA’s guidance notes that a voluntary registration can be backdated, but only by up to 30 days from the date CRA receives your request. (Canada.ca)
Once you’re registered, voluntarily or not, you have to charge and remit GST/HST on taxable supplies. CRA notes that registrants generally have to stay registered for at least one year before they can ask to cancel.
Why many contractors register early
This isn’t advice for your situation, but here’s why many trade businesses register before they hit $30,000:
- Input tax credits (ITCs). As a registrant, you can generally claim back the GST/HST you pay on business purchases (tools, materials, fuel, equipment) through ITCs. A small supplier who isn’t registered can’t, so the tax you pay on materials is just a cost.
- GCs and commercial clients. Many general contractors and commercial clients are registered themselves and can claim back the HST you charge them, so registering usually doesn’t make you more expensive to them. Some prefer working with registered subs.
- No single-quarter surprise. If you’re already registered, you’re already charging HST, so Scenario B can’t catch you out.
The trade-off: if most of your clients are homeowners who can’t claim the HST back, registering early makes your price to them 13% higher in Ontario. Run the numbers with your accountant.
What rate to charge
The rate depends on the province where the supply is made, not just where your business is. CRA’s current rates for the harmonized provinces:
| Province | HST rate |
|---|---|
| Ontario | 13% |
| Nova Scotia | 14% (since April 1, 2025) |
| New Brunswick | 15% |
| Newfoundland and Labrador | 15% |
| Prince Edward Island | 15% |
Other provinces and territories use the 5% GST, plus any separate provincial sales tax rules. Confirm rates on CRA’s GST/HST rates page before you set up invoicing, especially if you work across provincial lines.
How to track the $30,000 threshold
If you aren’t registered yet, check this at the end of every calendar quarter:
- Total each calendar quarter’s taxable revenue, before expenses. Use invoice totals, not deposits in the bank.
- Add the last four quarters together. If you’re getting close to $30,000, plan for registration.
- Look at the current quarter on its own. If a single job could take this quarter past $30,000, register before invoicing it.
- Include all your businesses (and ask your accountant about associates).
- Keep a simple log with quarter, revenue and running four-quarter total, so you can show your work if CRA asks.
A spreadsheet is enough. Most accounting software can also run a revenue-by-quarter report.
Quoting tips so the HST doesn’t eat your margin
- Write “plus HST” on quotes once you’re registered, or could be registered by the time you invoice.
- On big jobs near the threshold, register first. That’s the cleanest way to avoid the single-quarter trap.
- Show your GST/HST number on invoices once registered. CRA has specific invoice-information requirements, and your clients need your number to claim ITCs.
- Don’t treat collected HST as income. Move it to a separate account so remittance day isn’t painful.
Common mistakes contractors make with the small supplier rule
Counting only labour. If you supply and install, the material part of your invoice is part of your taxable revenue too. A sub who charges $8,000 for a job that includes $5,000 of materials has $8,000 of revenue for the threshold, not $3,000.
Using the calendar year instead of a rolling window. Being under $30,000 for January to December doesn’t settle the question. CRA looks at any four consecutive calendar quarters, so check every quarter, not once a year.
Waiting for the money to arrive. Contractors often think in terms of cash received, especially when holdback is being held back or a GC pays late. Track your invoiced taxable supplies and confirm with your accountant how timing rules apply to your invoices. Don’t assume a payment that hasn’t arrived yet doesn’t count.
Forgetting a second business. If you run a side business (snow removal, equipment rental, a small online store), its taxable revenue can count toward the same $30,000 total, because CRA’s test covers all your businesses.
Assuming the GC will “sort out the HST.” Your HST registration and remittances are your responsibility. If a GC pays you a lump sum with no HST on a job that should have carried it, CRA can still treat the tax as owing.
Registering and then not filing. Once you’re registered you’ll have GST/HST returns to file on CRA’s schedule, even for periods with little or no revenue. Put filing deadlines on your calendar the day you register.
Frequently asked questions
Is the $30,000 threshold based on profit?
No. CRA measures it as total revenue from taxable supplies before expenses. (Canada.ca)
Is it $30,000 per year?
Not exactly. It’s $30,000 over the last four consecutive calendar quarters, or $30,000 in a single calendar quarter.
What happens if one big job puts me over in a single quarter?
You stop being a small supplier and must charge HST on the supply that put you over the threshold. You then have 29 days from that supply to register. (Canada.ca)
Can I register before I reach $30,000?
Yes. Voluntary registration is allowed and can be backdated up to 30 days. Once registered, you must charge and remit HST.
What’s the HST rate in Ontario?
13%.
Sources
- Canada Revenue Agency, When to register for and start charging the GST/HST: https://www.canada.ca/en/revenue-agency/services/tax/businesses/topics/gst-hst-businesses/when-register-charge.html
- Canada Revenue Agency, GST/HST rates: https://www.canada.ca/en/revenue-agency/services/tax/businesses/topics/gst-hst-businesses/charge-collect-which-rate/calculator.html
Not legal or tax advice. Tax rules change, and how they apply depends on your facts. Confirm with the CRA or a qualified accountant.