When do I need to register for GST/HST in Canada?

The $30,000 small supplier threshold explained

You must register for GST/HST once taxable revenue exceeds $30,000. The test runs two ways, and either one triggers registration:

• Revenue exceeds $30,000 in a single calendar quarter — you must register immediately and charge tax on the sale that pushed you over
• Revenue exceeds $30,000 over four consecutive calendar quarters — you must register by the end of the month following that quarter

The threshold measures worldwide taxable supplies, not just Canadian sales, and it is gross revenue rather than profit. Zero-rated supplies count toward it; exempt supplies do not.

Why voluntary registration usually pays

Registering below the threshold lets you claim input tax credits on the GST/HST you pay on business purchases. For a business investing in equipment, software, professional fees or inventory, those credits are often worth more than the administrative burden.

The calculation flips based on your customers. If you sell to other registered businesses, they recover the tax you charge, so charging it costs you nothing competitively. If you sell to consumers, adding 5% to 15% to your price is a real disadvantage and voluntary registration may not be worth it.

Voluntary registration also lets you recover tax on startup costs incurred before you had revenue, which for a capital-intensive launch can be substantial.

What happens if you register late

Late registration does not excuse you from the tax. The CRA will assess GST/HST on all sales made after the date you should have registered, whether or not you collected it from customers. In practice that means paying it out of your own margin, because going back to past customers for tax you failed to charge is rarely successful.

Interest accrues on the assessed amount, and penalties may apply. If you discover you are late, the Voluntary Disclosures Program may reduce penalties and part of the interest if you come forward before the CRA contacts you.

Choosing your filing frequency

Your reporting period depends on annual taxable revenue:

• Up to $1.5 million — annual filing by default, with quarterly or monthly optional
• $1.5M to $6M — quarterly by default, monthly optional
• Over $6 million — monthly, mandatory

Filing more often than required is sometimes deliberate. A business in a persistent refund position, such as an exporter with zero-rated sales, recovers cash faster on monthly filing rather than waiting a year.

The Quick Method and when it helps

The Quick Method lets eligible small businesses remit a flat percentage of GST/HST-included sales rather than tracking every input tax credit. Eligibility generally requires annual taxable supplies under $400,000.

It benefits service businesses with low purchase volumes, where the flat rate remits less than the tax collected and the difference is kept. It is a poor choice for businesses with significant taxable purchases, because you forgo most input tax credits. We model both before electing, since the election binds you for at least a year.

Provincial differences that catch people out

Registering for GST/HST does not necessarily cover your provincial obligations. In British Columbia, Saskatchewan and Manitoba, provincial sales tax is a separate registration, a separate return, and a separate authority — and unlike GST, it generally cannot be recovered as an input tax credit.

Quebec administers both GST and QST through Revenu Quebec rather than the CRA. Alberta has no provincial sales tax at all. HST provinces such as Ontario, Nova Scotia and New Brunswick combine both into one return, which is the simplest arrangement.