GST/HST Registration: When Does Your Canadian Business Have to Register?

The $30,000 Small Supplier Threshold

You must register for a GST/HST account once your total taxable revenue exceeds $30,000 ($50,000 for public service bodies)—measured two ways: over any single calendar quarter, or over any four consecutive calendar quarters. The $30,000 figure is not indexed to inflation and has stayed fixed for years.

Taxi drivers and commercial ride-share drivers (including Uber) must register regardless of income—there is no small supplier exemption for this category. The GST/HST registration threshold is one of the most important numbers for Canadian small business owners to understand. Crossing this threshold triggers significant changes to your business operations, including the requirement to charge GST/HST on your sales, issue tax invoices, and file regular GST/HST returns.

How the Calculation Actually Works

This is where businesses get tripped up: the CRA does not look at your calendar year or fiscal year—it looks at any four consecutive calendar quarters. You could earn $10,000 in Q1, $8,000 in Q2, $7,000 in Q3, and $6,000 in Q4—that is $31,000 across four quarters, and you must register, even though no single quarter looked alarming.

If you exceed $30,000 in one single quarter, you become a registrant immediately—your effective registration date is the day of the sale that pushed you over, and you must charge GST/HST on that very sale, even though you were not registered yet when you made it.

The rolling four-quarter test is the most common source of confusion. Many business owners check their total revenue for the calendar year and assume they are safe, without realizing that the CRA looks at any four consecutive quarters. This means you could exceed the threshold in the middle of the year and be required to register immediately, even if your total revenue for the calendar year is still below $30,000.

The 29-Day Window

Once you cross the threshold, you have 29 days to formally register with the CRA. As of November 3, 2025, the CRA no longer accepts GST/HST registration by phone—all new registrations must go through the Business Registration Online (BRO) platform.

What Counts Toward the Threshold

Include all worldwide revenue from taxable supplies (including zero-rated supplies like exports and basic groceries) across all your business activities and associated entities. Exclude revenue from financial services, sales of capital property, and goodwill from a business sale. Employment income does not count—if you earn $80,000 as an employee plus $25,000 freelancing, only the $25,000 applies to the threshold test.

HST Rates by Province

HST (harmonized) applies in Ontario (13%), Nova Scotia (15%), New Brunswick (15%), Newfoundland and Labrador (15%), and PEI (15%). Other provinces apply the federal 5% GST separately alongside their own provincial sales tax.

Should You Register Voluntarily Below $30,000?

Many freelancers and startups register before they are required to, specifically to claim Input Tax Credits (ITCs) on GST/HST already paid on equipment, software, and other business expenses. The trade-off: once registered voluntarily, you must charge and remit GST/HST on every sale going forward, even while still under $30,000.

The Real Cost of Missing the Deadline

If you do not register when required, the CRA can assess you for all the GST/HST you should have collected, plus interest and penalties—and you remit it out of your own pocket, since you never charged customers for it. You may also lose the ability to claim ITCs for that period.

Coming Into Compliance Voluntarily

If you have discovered you should have registered months ago, the CRA's Voluntary Disclosure Program may help you correct the situation with reduced penalty exposure compared to being caught through a routine review.

Conclusion: Get GST/HST Registration Right from Day One

Understanding the $30,000 small supplier threshold, the rolling four-quarter test, and the 29-day registration window is essential for every Canadian small business owner. The consequences of missing the deadline can be significant, including backdated GST/HST liabilities, penalties, and interest.

If you are unsure whether you have crossed the threshold, or need help registering correctly, our team at CA-Sir helps Canadian businesses and freelancers navigate GST/HST registration from day one. Contact us today to book a consultation.