When to Register for GST/HST (Small Supplier Threshold)

Introduction
Understanding when to register for GST/HST is essential for freelancers, consultants, self-employed professionals, corporations, online sellers, tradespeople and gig-economy workers in Canada. The GST/HST registration rules apply to anyone carrying on a commercial activity in Canada—whether part-time, full-time or seasonal. The most important rule is the small supplier threshold, which determines when a business must begin collecting and remitting sales tax. Many new business owners misunderstand the threshold, register too late, or fail to register entirely, leading to CRA reassessments, interest charges and penalties. Québec adds another layer of requirements through its separate QST system. This guide explains exactly when to register for GST/HST, how the small supplier threshold works, and how to remain compliant across Canada.

Legal and Regulatory Framework
When to register for GST/HST is governed by the Excise Tax Act and, in Québec, by the Taxation Act. A person or business must register for GST/HST if:

• their worldwide taxable revenues exceed $30,000 in any single calendar quarter, or
• their worldwide taxable revenues exceed $30,000 over four consecutive calendar quarters, or
• they expect to exceed $30,000 in the current quarter, or
• they operate a taxi or rideshare business (mandatory regardless of revenue), or
• they are a non-resident carrying on business in Canada (with special rules)

Worldwide taxable revenues include sales from all businesses the person operates—not just one activity.

Once a business crosses the small supplier threshold Canada requires immediate GST/HST registration. Businesses must begin charging GST/HST on all taxable goods and services, file regular returns, and remit collected tax to the CRA.

Québec residents must also register for QST once they exceed the Québec threshold or carry on taxable activities in the province. Understanding when to register for GST/HST requires tracking revenue carefully throughout the year.

Key Court Decisions
Courts have issued several rulings clarifying when to register for GST/HST. Important principles include:

• crossing the threshold obligates immediate registration—even if the business owner is unaware
• CRA may assess GST/HST retroactively if the business failed to register
• taxes charged but not remitted are a serious compliance offence
• platform-based businesses (Uber, Lyft, Airbnb) must comply with mandatory rules
• worldwide revenue, not just Canadian revenue, counts toward the $30,000 calculation
• “splitting” activities into multiple small businesses does not avoid the threshold

Québec courts also ruled that businesses failing to register for QST in time must pay backdated QST plus interest. These decisions highlight how strictly the small supplier threshold is enforced.

Why CRA Targets This Issue
CRA closely monitors when to register for GST/HST because:

• many small businesses incorrectly assume GST doesn’t apply to them
• Uber and rideshare drivers often misunderstand mandatory registration
• online sellers often fail to track revenue accurately
• delivery workers confuse gross vs net revenue from platforms
• consulting or service-based businesses surpass $30,000 quickly without realizing it

Audit triggers include:

• income reported on tax returns exceeding $30,000 without GST filings
• platform data showing earnings above the threshold
• inconsistent GST/HST filings compared to business activity
• businesses charging GST without a valid registration number
• repeated late registrations

Revenu Québec applies similar triggers for QST. Understanding when to register for GST/HST prevents sudden reassessments and unexpected liabilities.

Mackisen Strategy
Mackisen CPA provides a structured approach to determining when to register for GST/HST:

• tracking gross revenue across all business activities
• confirming whether the small supplier threshold has been exceeded
• determining which provinces require GST or HST based on place-of-supply rules
• registering for GST/HST immediately when required
• registering separately for QST in Québec
• setting up proper invoicing systems with tax codes
• calculating backdated GST/HST if registration was late
• filing voluntary disclosures when necessary to reduce penalties
• reconciling GST/HST with revenue and expenses
• preparing accurate periodic returns

Our approach ensures full compliance with CRA and Revenu Québec requirements.

Real Client Experience
Many clients come to Mackisen after unknowingly exceeding the small supplier threshold Canada enforces. One freelancer earned over $42,000 but believed GST applied only once profits, not revenues, crossed $30,000. CRA reassessed the full year’s GST. Mackisen filed a voluntary disclosure to reduce penalties.

A Québec contractor exceeded the threshold but failed to register for QST. Revenu Québec demanded retroactive filings. We corrected the account and negotiated interest relief.

One Uber driver assumed the platform handled GST. While the app collects GST from riders, GST registration remains mandatory. Mackisen registered the client and ensured all filings were compliant.

An online Shopify business exceeded $30,000 in two months but kept operating as a small supplier. CRA audited and assessed missing GST. We rebuilt sales records and corrected past returns. These cases show why knowing when to register for GST/HST is critical.

Common Questions
Business owners frequently ask:

• Do I register based on revenue or profit?
Revenue—profits don’t matter.

• If I earn $29,999 do I register?
No—unless you voluntarily register or operate a rideshare business.

• Is GST/HST mandatory for Uber drivers?
Yes—regardless of income.

• What if I exceed the threshold halfway through the year?
Registration becomes mandatory immediately.

• Does Québec require its own registration?
Yes—QST requires a separate registration number.

• What if I forget to register?
CRA may assess backdated GST/HST plus interest.

Understanding these answers ensures businesses comply with when to register for GST/HST rules.

Why Mackisen
With more than 35 years of combined CPA experience, Mackisen CPA Montreal helps businesses stay compliant while recovering the taxes they’re entitled to. Whether you're filing your first GST/QST return or optimizing multi-year refunds, our expert team ensures precision, transparency and protection from audit risk. When advising clients on when to register for GST/HST, Mackisen provides revenue tracking, registration support, voluntary disclosures and full sales-tax compliance services.