When to Register for and Start Charging the GST/HST — Montreal CPA Firm Near You: Small Supplier Rules, Effective Dates, Threshold Calculations, Special Cases, and CRA Compliance

Understanding when to register for and begin charging the Goods and Services Tax (GST) or Harmonized Sales Tax (HST) is one of the most important legal obligations for any business in Canada. Whether you operate a small consulting practice, an online store, a corporation, a ride-sharing business, a non-resident digital service, or a charity, GST/HST compliance determines your tax responsibilities, filing rules, and input tax credit (ITC) eligibility. Mistakes can lead to costly reassessments where you end up paying GST/HST out of your own pocket, along with penalties and interest.

This complete Mackisen CPA guide explains everything you need to know: who must register, who is exempt, how the $30,000 small supplier limit works, how CRA calculates registration dates, why taxi and ride-share drivers must register immediately, how non-residents selling into Canada must comply, and how charities, public service bodies, and selected listed financial institutions follow different rules. Optimized with primary SEO keywords such as GST/HST registration Canada, when to start charging GST HST, CRA small supplier threshold, GST registration rules and secondary keywords such as Montreal CPA GST/HST help, CRA business number registration, voluntary GST account Canada this guide is designed to maximize clarity, learning, and high-value client conversions.

GST/HST Registration Modern Updates and CRA Policy Changes

As of June 17, 2024, CRA now allows individuals whose Social Insurance Number begins with “9”—typically temporary residents, international student workers, and foreign nationals authorized to work—to register for a business number and GST/HST account using Business Registration Online (BRO). This modernizes access and removes delays that previously required mailed or in-person verification.

A major CRA administrative change is coming. Effective November 3, 2025, business registration by phone will end permanently. CRA will no longer accept business number (BN) and GST/HST program account registrations by telephone. All registrations must be completed through Business Registration Online or through a professional representative such as Mackisen CPA using secure CRA authorization. This marks a major shift toward digital compliance and requires every business owner to understand online registration.

Who Must Register for a GST/HST Account

You must register for GST/HST if you:

Are not a small supplier, and
Make taxable sales, leases, or supplies in Canada (unless your only taxable supplies relate to the sale of real property outside the course of business).

Taxable supplies include goods and services taxed at 5%, 13%, or 15%, as well as zero-rated supplies taxed at 0%. You cannot register if your business supplies only exempt goods or services such as residential rentals, most medical services, childcare, or financial services. These businesses do not charge GST/HST and cannot claim input tax credits.

If you are a selected listed financial institution making reporting entity, consolidated filing, or tax adjustment transfer elections, you must review GST/HST Notice 265 for specialized registration procedures.

Understanding the nature of your supplies is crucial. Mackisen reviews your business model to ensure compliance, correct classification of supplies, and alignment with CRA expectations.

Understanding the Small Supplier Rule

A “small supplier” is a business whose worldwide taxable revenues (before expenses) from all associated entities do not exceed $30,000 over four consecutive calendar quarters. Until you exceed this threshold, you generally do not have to register. CRA applies different rules depending on how and when you cross this limit. Each scenario determines when you must register and when you must begin charging GST/HST.

Scenario 1: You Do NOT Exceed the $30,000 Threshold Over Four Consecutive Calendar Quarters

If your total worldwide taxable revenues stay under $30,000:

You are a small supplier.
You do not have to register.
You may register voluntarily if you make taxable supplies.
Your effective date of registration is the day you request it, or up to 30 days earlier.

Voluntary registration allows you to claim input tax credits (ITCs) on business expenses. Many new businesses voluntarily register because they incur high startup costs that would otherwise be unrecoverable.

Scenario 2: You Exceed the $30,000 Threshold in a Single Calendar Quarter

This is the most important and most commonly misunderstood rule. If you exceed $30,000 in a single quarter:

You are no longer a small supplier immediately.
You must charge GST/HST on the supply that pushed you over $30,000.
Your registration deadline is the day of that supply.
Your effective date of registration is the exact date the threshold was exceeded.

This means that even if you were not registered at the time, CRA expects GST/HST to be charged. If you fail to do so, CRA will make you remit the GST/HST from your own funds. Mackisen helps clients correct errors and avoid retroactive tax liabilities.

Scenario 3: You Exceed the $30,000 Threshold Over Four (or Fewer) Consecutive Calendar Quarters, But Not in One Quarter

If your cumulative total exceeds $30,000 over any four consecutive quarters:

You cease being a small supplier at the end of the month after the quarter in which you exceeded $30,000.
You must register for GST/HST no later than your next taxable supply.
Your effective date of registration is the date of that next supply.
You must begin charging GST/HST starting on that date.

This scenario typically impacts freelancers, service providers, and small online sellers experiencing slow but steady growth.

Important Revenue Calculation Notes (Footnote 1 Expanded)

For sole proprietors:
You must include total revenues from all worldwide taxable supplies from all your businesses plus revenues from any associated businesses.

For partnerships or corporations:
You must include all worldwide taxable supplies and include associated entity revenues if associated at the beginning of the quarter.

Revenues that do NOT count toward the threshold include:

Supplies of financial services
Sales of capital property
Goodwill from the sale of a business

Mackisen helps identify associated entities, which is often misunderstood and leads to costly compliance errors.

Calendar Quarter Definitions (Footnote 2 Expanded)

A calendar quarter is:

January 1–March 31
April 1–June 30
July 1–September 30
October 1–December 31

Your four-quarter rolling calculation must always reflect the current quarter plus the previous three.

Additional GST/HST Registration Rules for Special Categories

Charities

Charities have a higher small supplier threshold of $50,000 and may qualify for rebates. They must track exempt vs taxable activities carefully. GST/HST registration affects reimbursement eligibility.

Public Service Bodies

Public service bodies include municipalities, universities, school boards, hospital authorities, and non-profits. These organizations may be required to register depending on their revenues and activities.

Non-Residents

Non-residents selling taxable goods or digital services to Canadian customers may need to register even without physical presence. New cross-border e-commerce rules require many non-residents to register once they supply taxable digital services to Canadian consumers.

Taxi Operators and Ride-Share Drivers

All taxi drivers and all commercial ride-sharing drivers (Uber, Lyft, etc.) must register from the first dollar earned. They are never considered small suppliers. Registration is mandatory immediately upon beginning operations.

Mackisen registers ride-share drivers and guides them through deductions, recordkeeping, and ITC eligibility.

Voluntary Registration: When It Makes Sense

Voluntary registration is beneficial when:

You incur significant business expenses and want to claim input tax credits
Your clients are businesses that can recover ITCs anyway
You want to appear established and fully compliant
You expect to surpass $30,000 soon and want to avoid sudden retroactive obligations

Voluntary registration must be managed carefully to avoid unnecessary filing obligations.

Consequences of Failing to Register On Time

Failing to register when required leads to:

CRA forcing you to remit GST/HST out of your own pocket
Penalties and interest on uncollected tax
Audits and compliance reviews
GST/HST owing applied to personal refunds
Potential payroll or income tax cross-matching audits

Many small businesses learn this too late—after CRA reassesses several years backward. Mackisen corrects backdated GST/HST issues and prevents future non-compliance.

Why Mackisen

With over 35 years of combined CPA experience, Mackisen CPA Montreal helps businesses determine exactly when to register, how to calculate the small supplier threshold, how to classify supplies correctly, and how to comply with GST/HST rules without penalties. Whether you are a freelancer, corporation, charity, ride-share driver, non-resident seller, or service provider expanding your business, Mackisen ensures proper registration, accurate filing, and full compliance with CRA.

If you want expert guidance calculating thresholds, registering correctly, or avoiding CRA reassessments, Mackisen ensures you charge GST/HST at the right time, every time.