GST/HST Registration in Canada: Complete Guide for Small Businesses (2026)

If you run a small business in Canada, one question eventually lands on your desk: do you need to register for GST/HST, and when? GST registration Canada rules are not complicated once you understand the $30,000 threshold, but getting the timing wrong can cost you penalties, back taxes, and a stressful call from the CRA. This guide walks you through everything a small business owner needs to know about HST registration, getting a GST number Canada, and staying compliant in 2026.

GST (Goods and Services Tax) is a 5% federal tax charged on most goods and services sold in Canada. Five provinces Ontario, Nova Scotia, New Brunswick, Newfoundland and Labrador, and Prince Edward Island combine the federal and provincial tax into a single rate called HST (Harmonized Sales Tax). The remaining provinces charge 5% GST, sometimes alongside a separate provincial sales tax.

For a small business, GST/HST is not really “your” money. You collect it from customers and remit it to the CRA. Once you understand that distinction, the whole system becomes far less intimidating and registering on time simply means you’re collecting correctly from day one instead of scrambling to fix it later.

This is the single most important number in small business GST compliance. If your worldwide taxable revenue stays at or under $30,000, you’re considered a “small supplier” and registration is optional. Cross that line, and registration becomes mandatory. The CRA applies two separate tests, and tripping either one ends your small-supplier status.

The Four-Quarter Test

The CRA looks at your taxable revenue over any four consecutive calendar quarters not your calendar year or fiscal year. If that rolling total goes above $30,000, you must register for GST/HST, even if no single quarter looked alarming on its own.

The Single-Quarter Test

If one calendar quarter alone brings in more than $30,000 in taxable revenue, you lose small-supplier status immediately, on the date of that sale. There’s no grace period here. You must charge GST/HST on the very transaction that pushed you over, and you generally have 29 days to register for GST/HST with the CRA.

A single large invoice, a seasonal spike, or one big client contract is often what catches growing businesses off guard. Tracking your revenue monthly, rather than waiting until tax season, is the easiest way to avoid an unpleasant surprise.

Registering for GST/HST is more straightforward than most business owners expect, especially now that the CRA has moved almost entirely to online registration.

Step 1 — Gather Your Business Information

Before you start, have your legal business name, business structure (sole proprietor, partnership, or corporation), Social Insurance Number or existing Business Number, and an estimate of your annual revenue ready.

Step 2 — Register Online Through the CRA’s Business Registration Online (BRO)

2026 Safety & Access Note: As a mandatory update for July 2026, the CRA has enhanced portal security. You can no longer access the BRO directly; business owners must first sign in securely via their personal CRA account (My Account) or My Business Account, from where the Business Registration Online portal can be accessed safely.

Most businesses can register for GST/HST online through the CRA’s Business Registration Online portal. As of late 2025, the CRA no longer accepts GST/HST registration by phone, so the online route is now the standard way to register for GST/HST.

Step 3 — Receive Your Business Number and GST/HST Account

If you don’t already have one, you’ll be issued a nine-digit Business Number (BN) on the spot. Your GST/HST account is added to that BN with an RT0001 suffix for example, 123456789 RT0001. This is your official GST number Canada businesses use on every invoice.

Step 4 — Confirm Your Effective Date and Filing Frequency

You’ll also set your effective date of registration, which for mandatory registrants is the date of the sale that pushed you over $30,000, and your filing frequency (monthly, quarterly, or annually), which is generally based on your estimated annual revenue.

Many Canadian small businesses register for GST/HST before they’re legally required to. If most of your clients are other GST/HST-registered businesses, charging tax costs them nothing since they simply claim it back as an input tax credit. Meanwhile, voluntary registration lets you claim input tax credits on your own start-up costs software, equipment, contractor invoices, and professional services. For a business spending heavily in its early months, that can add up to real savings.

Voluntary registration isn’t automatically the right move for every business. Businesses selling mainly to individual consumers, for example, may prefer to stay under the threshold as long as possible to keep prices lower. This is exactly the kind of decision worth reviewing with an accountant before you commit.

Once registered, you must charge GST/HST on every taxable sale, include your GST/HST number on all invoices, file returns for every reporting period even if you had zero sales and remit any tax collected by your due date. You can also start claiming input tax credits (ITCs) to recover the GST/HST you pay on eligible business expenses.

The CRA requires that all GST/HST records be kept for six years. Clean, organized bookkeeping from day one makes filing far less stressful and protects you if the CRA ever reviews your account.

• Waiting until year-end to check revenue instead of tracking it monthly against the $30,000 threshold.
• Assuming incorporation exempts a business from GST/HST — it does not.
• Charging the wrong rate by using their own province instead of the customer’s location (place of supply rules).
• Missing the 29-day registration deadline after crossing the threshold in a single quarter.
• Not registering voluntarily when it would have unlocked valuable input tax credits.

GST/HST rules are full of small details that are easy to get wrong from choosing your effective date to setting the right filing frequency for your business. If you’d rather have a professional handle it correctly the first time, the team at Tax Square PC works with small businesses across Canada on GST registration, HST registration, bookkeeping, and ongoing CRA compliance.

You can learn more about their small business tax services at https://taxsquarepc.ca/, where their accountants help business owners register for GST/HST, choose the right filing frequency, and stay audit-ready year-round.

GST/HST registration isn’t something to put off until the CRA comes asking. Understanding the $30,000 threshold, registering on time, and keeping clean records from the start will save you money, stress, and unnecessary penalties down the road. If you’re unsure where your business stands, a quick conversation with a Canadian tax professional, like the team at Tax Square PC, can save you from an expensive mistake later.

1. Do I need to register for GST/HST if I’m a sole proprietor?

 Yes, if your worldwide taxable revenue exceeds $30,000 in a single calendar quarter or over four consecutive quarters, registration is mandatory regardless of your business structure, including sole proprietors and freelancers.

2. How long does it take to get a GST number in Canada? 

If you register online through the CRA’s Business Registration Online portal, you typically receive your Business Number and GST/HST account instantly.

3. What happens if I don’t register for GST/HST on time? 

The CRA can assess you for the GST/HST you should have collected, along with penalties and interest, even if you never actually charged your customers. You may also lose the ability to claim input tax credits for that period.

4. Can I register for GST/HST before I reach the $30,000 threshold? 

Yes. Voluntary registration is available to small suppliers and can be a smart move if you have significant start-up expenses or sell mainly to other GST/HST-registered businesses.

5. How often do I need to file GST/HST returns? 

Your filing frequency monthly, quarterly, or annually is generally set by the CRA based on your estimated annual taxable revenue, though you can request a more frequent filing period if you prefer.