When do I have to register for GST/HST and QST? The $30,000 threshold

Almost every Canadian business starts out as a small supplier: it sells, it invoices, and it charges no GST, no HST and no QST, because below $30,000 it is not required to. Then one month the invoices get bigger, and the question arrives — am I over? The answer turns on a test that is more precise than most people expect, and on a date that is easy to get wrong by a quarter. This page sets out what the $30,000 actually measures, the two different ways of crossing it, what happens on the day you do, why registering early is sometimes the better business decision, and how the Québec QST rides alongside the federal tax. KRONENWERK is not a tax adviser, and nothing here is advice: your own case belongs with your accountant.

What the $30,000 actually measures

The threshold is not your profit, not your bank balance and not your Canadian sales. It is the total consideration for your worldwide taxable supplies — everything you sell that is taxable, including sales that are zero-rated, and including exports. A Montréal consultancy billing $28,000 to clients in Vermont has $28,000 against the threshold even though it charged no tax on any of it. That surprises people every year.

Three things come out of the count. The Canada Revenue Agency excludes the consideration for goodwill attributable to the sale of a business, supplies of financial services, and supplies made by way of sale of capital property. Exempt supplies are outside the count altogether, as is any GST/HST that would have been collected. And the count is not yours alone: the supplies of your associates are added to yours, which is what stops a business being split into four companies of $29,000 each. Whether two entities are associated is a statutory test with real edges, and it is a question for your accountant, not for a threshold table.

One more detail that trips up anyone with a June or September year end: the quarters are calendar quarters — January to March, April to June, July to September, October to December — regardless of your own fiscal year. Your bookkeeping year is irrelevant to this test.

The two tests, side by side

There is not one threshold test but two, and they have different consequences. The difference is the single most useful thing on this page, because the tests differ not in the amount but in when you stop being a small supplier.

In both cases the CRA requires you to register within 29 days of your effective date of registration. Note what that means: the effective date can already be in the past by the time you notice. Missing it does not remove the obligation — it leaves you owing tax on invoices that did not charge any, which you then have to go back to your customers about, or absorb.

The day you cross it

On the effective date, several things change at once. You are a registrant: you charge GST or HST on your taxable supplies at the rate that applies to the place of supply, you print your registration number on your invoices, you file returns on the frequency the CRA assigns you, and you may claim input tax credits on your business purchases. The tax you collect is not revenue — it is money you hold on the CRA's behalf until you remit it, and treating it as cash flow is the classic first-year mistake.

Which rate applies is a separate question from whether you must register. The federal GST is 5 %. Some provinces instead levy a harmonized tax (HST) at a single combined rate — Ontario at 13 %, Nova Scotia at 14 % since 1 April 2025, and others at their own rates. Others levy a separate provincial sales tax alongside the 5 % GST. Québec levies the QST at 9.975 %. Registering for GST automatically covers you for the HST; the QST is a separate registration. Determining the correct rate for a given customer in a given province is your accountant's territory and yours, not a piece of software's.

Registering voluntarily, and why it can pay

If you make taxable supplies in Canada, you may register even while you are still under the threshold. You generally cannot register if everything you supply is exempt.

The reason to do it is the input tax credit. A registrant recovers the GST/HST paid on business purchases and operating expenses — equipment, software, professional fees, materials — against the tax it collects. An unregistered small supplier pays that tax and keeps it as a cost. For a business with heavy start-up spending, or one selling mostly to registered business customers who will simply reclaim whatever you charge them, voluntary registration often puts money back rather than taking it away. For a business selling to consumers who cannot reclaim anything, adding 5 % or more to the price is a real competitive question.

The CRA's rule on timing is that if you request the account while you are still a small supplier, the effective date is usually the date of your request, and can generally be backdated up to 30 days. A corporation's registration cannot predate its incorporation. And it is not a decision you can unwind next month: you must stay registered for at least one year before you can cancel, unless you stop your commercial activities.

What changes on your invoices

From the effective date, your invoices change in ways your business customers will notice immediately. Your GST/HST registration number belongs on the document — the nine-digit business number followed by RT and a four-digit reference, in the form 123456789RT0001 — because without it your customer's bookkeeper cannot claim the input tax credit. The tax must be shown as an amount, or as a statement that the total includes tax with the rate stated. Where you charge two taxes, they are shown as two lines with two rates and two amounts, never merged. The detailed rules by invoice amount are in what a Québec invoice must show; the export case is in invoicing a US customer from Canada.

The reverse also holds, and it is the sharper rule: before you are registered, you must not charge the tax. Collecting GST with no registration number to print is not a harmless head start — it is an amount collected that you have no account to remit it through.

The Québec QST alongside it

Revenu Québec applies the same $30,000 figure and the same structure: registration is mandatory once your total worldwide taxable supplies exceed $30,000 in a given calendar quarter or in the four preceding calendar quarters. A Québec business crossing the threshold therefore normally acquires two registrations and two numbers — the federal RT number and a QST number in the form 1234567890TQ0001.

Québec then adds cases where registration is mandatory regardless of how small you are. A taxi business must register, and a driver supplying commercial ride-sharing services is deemed to be a taxi business by the CRA and must register and charge tax on their fares whatever their revenue. Revenu Québec requires QST registration even from small suppliers for retail sales of tobacco, retail sales of fuel, sales of alcoholic beverages (with an exception for reunion permit holders), sales or leasing of new tires, and sales or long-term leasing — twelve months or more — of road vehicles. Non-residents charging admission to public events in Québec must register too. If your business is in one of those categories, the $30,000 test does not apply to you at all, and you should confirm your position with your accountant before your first invoice rather than after it. Practical guidance for a Québec business is on the Montréal page, and the country-level picture on the Canada page.

Where this page stops and your accountant starts

Several parts of these rules have genuine nuance that no general page can settle, and getting them wrong costs money. Your exact effective date of registration depends on which test you crossed and on the date of a specific supply, and identifying that supply in a real ledger is not always obvious — it requires professional confirmation. Which test you crossed matters more than it looks: the single-quarter case gives no grace month, the four-quarter case does, and a business that assumes the wrong one under-collects or over-collects. Public service bodies — charities, non-profits, municipalities, schools, hospitals — have a different threshold of $50,000, and charities and public institutions have a separate $250,000 gross revenue test with its own conditions by fiscal year; that regime is its own subject and belongs with an adviser who knows it. Non-resident businesses and their Canadian registration obligations, including the simplified and specified regimes, turn on where supplies are made and are not covered here. Taxi and ride-share operators should take the deeming rule seriously. And in Québec, individuals, personal trusts and partnerships made up only of individuals cannot register if they operate without a reasonable expectation of profit or supply only tax-exempt property or services. On all of these: confirm with your accountant, and treat the CRA and Revenu Québec pages cited above as the authority.

How KRONENWERK handles this

SUPPORTED WITH LIMITATIONS KRONENWERK records your GST/HST and QST registration numbers on the company and prints them on every invoice from the tier upward. It computes GST and QST — or HST, or GST plus PST — as separate lines on the net, each with its rate and amount. It refuses to charge QST when no QST registration is on file, and it warns when a document's tax structure does not match the customer's province. Issued documents are frozen with gap-free numbering and six-year retention of attachments, and the figures per rate and category are in the reports. Not done: it does not file the GST/HST or QST return, it does not decide whether you must register, it does not determine rates, and it gives no tax advice. Four plans from 29 € a month, no free plan and no trial — see pricing and invoices.