GST/HST Registration in Canada: Thresholds, Timing and the Quick Method

GST/HST registration is one of the few tax obligations in Canada that arrives on a schedule you do not control. You do not decide to register. Your revenue decides for you, and it decides retroactively if you are not watching.

That retroactivity is where the damage happens. The CRA’s position is straightforward, once you exceed the threshold, you were required to be registered, and you were required to be charging tax. If you were not charging, the tax still has to be remitted: out of your own margin.

The $30,000 threshold, precisely

You stop being a small supplier once your worldwide taxable revenue passes $30,000. Three details make this less simple than it sounds: It is a rolling four-quarter test, not a calendar year. You are measuring total taxable revenue across the last four consecutive calendar quarters, which is not the same as your fiscal year, and not the same as January to December.

It is gross revenue, not profit. Expenses are irrelevant to the test. A consultant billing $34,000 and netting $12,000 is over the threshold.

It counts associated businesses. Revenue of associated persons is included. Running two small ventures does not give you two thresholds.

The CRA sets out the full test in when to register for and start charging the GST/HST.

The timing trap that catches most people

There are two distinct moments, and confusing them is the single most common error.

If you exceed $30,000 in a single calendar quarter, you cease to be a small supplier immediately, and you must charge GST/HST on the supply that pushed you over. Not the next one: that one.

If you exceed $30,000 over four consecutive quarters but not in any single quarter, you cease to be a small supplier at the end of the month following that quarter. You have a short window, then the obligation starts.

In both cases the obligation to charge tax begins before most people have gotten around to registering. The registration itself can be backdated. The tax you failed to collect from a client eight months ago generally cannot be recovered from them: clients are not obliged to pay an invoice you send late, and many will simply decline.

Practical rule: watch your trailing twelve months monthly, and register when you cross roughly $27,000. The small amount of administration you take on early is trivial compared to eating the tax on a quarter of unbilled HST.

The two triggers, side by side

Why registering voluntarily is often the right move

You may register before you hit the threshold, and for many businesses that is the better decision.

The reason is input tax credits. Once registered, you recover the GST/HST you paid on business purchases: ITCs. Unregistered, that tax is simply a cost you absorb.

Voluntary registration usually makes sense when:

• Your clients are businesses. They claim the tax back, so charging it costs them nothing. Your price is effectively unchanged.
• You have meaningful startup costs. Equipment, software, professional fees, a vehicle. The ITCs on those can be substantial.
• You are approaching the threshold anyway. Registering on your own timing is calmer than registering retroactively.

It usually does not make sense when your customers are individuals who cannot recover the tax. Adding 13% to a consumer price is a real price increase, and in a competitive market it comes out of your volume. If you are running a consumer-facing side business, weigh this alongside the deduction planning in side hustle and gig work tax deductions.

Which rate you charge

The rate follows the place of supply: broadly, where your customer is, not where you are. An Ottawa consultant billing a client in Alberta charges 5% GST; the same consultant billing across the river in Gatineau faces different rules again.

Ontario is 13% HST. The Atlantic provinces are 15%. Alberta and the territories are 5% GST. British Columbia, Saskatchewan and Manitoba have 5% GST plus a separate provincial sales tax that is not administered by the CRA and is not part of your GST/HST return.

The place-of-supply rules for services and for digital products are more involved than a single paragraph allows, and the CRA sets them out in which rate to charge. For a business selling across provinces, this is worth getting right once rather than guessing per invoice.

The Quick Method, worth checking, frequently overlooked

The Quick Method is an election that changes how you calculate what you remit. Instead of tracking every input tax credit, you charge tax normally but remit a reduced percentage of your tax-included revenue, keeping the difference.

It is available below an annual taxable revenue ceiling, and it is not open to every type of business: accountants, bookkeepers, financial consultants and several other listed professions are excluded, which is worth knowing before you get attached to the idea.

Where it is available, the Quick Method tends to win for service businesses with low input costs: a consultant whose main expenses are their own time recovers very little through ITCs, so a flat reduced remittance rate is straightforward profit. It tends to lose for businesses that buy a lot of taxable goods.

Run the comparison on your actual numbers for one year before electing. The election has timing rules and you cannot switch back and forth freely.

Filing frequency and the cash flow trap

Your assigned filing frequency, annual, quarterly or monthly, depends on your revenue, and you can elect to file more often than required.

Filing annually sounds attractive. It is often a mistake. GST/HST you collect is not your money. It is held on behalf of the government, and an annual filer accumulates it for twelve months before remitting. Businesses spend it. Then the return comes due, and the cash is gone.

Quarterly filing keeps the number small enough to stay visible. If you file annually, open a separate account and move the tax into it as you collect. This is the same discipline that makes a monthly close work, see small business bookkeeping automation.

Note also that annual filers above a revenue threshold must make instalment payments during the year, which removes much of the supposed simplicity.

What good records look like

If you are ever reviewed, the questions are predictable: did you charge the correct rate, did you remit what you collected, and can you support every ITC you claimed.

The ITC side is where reviews usually find problems. A claim needs a supplier invoice containing specific information, including the supplier’s GST/HST registration number for larger amounts. A credit card statement is not sufficient. Neither is a receipt with no registration number.

Keep the invoices, keep them for six years, and check that the registration number is actually on them. What a CRA review looks like in practice is covered in HST/GST audit defence.

The short version

• The $30,000 test is rolling, gross, and includes associated businesses.
• Exceed it in one quarter and you charge tax on that supply immediately.
• Register at around $27,000 rather than waiting to be forced.
• Register voluntarily if you sell to businesses or have real startup costs.
• Check whether the Quick Method fits before dismissing it.
• File quarterly unless you have a specific reason not to.
• Keep supplier invoices with registration numbers on them.

If your revenue is climbing toward the threshold this year and you are not sure where you stand, that is a short conversation worth having early rather than at filing time.