Do I Need to Register for GST? Start With What You're Actually Selling

Most new business owners assume GST registration is just a matter of hitting a sales number. That's part of it — but it's not the first question. The first question is: what kind of thing are you actually selling? Because not everything gets taxed the same way, and that changes both whether you need to register and what registering actually does for you.

Before we get into that, here's one term worth knowing up front: when you buy things for your business — tools, materials, fuel, insurance — you're paying GST on those purchases too. If you're GST registered, in most cases you can claim that GST back, subtracting it from what you owe the CRA. That's called an Input Tax Credit, or ITC for short, and it's one of the most useful things about being registered. But whether you can use it depends entirely on what you sell — which is where we start.

Not All Sales Are Taxed the Same Way

Every sale a business makes falls into one of three categories under Canadian tax law. Which one your product or service falls into changes what you charge and what you can claim back.

Taxable. This is the default, and it's where almost everything sits — most goods, most services, most of what a typical trades or contracting business sells. GST gets charged on the sale at the standard rate (5% in Alberta, since we don't have a provincial sales tax layered on top). If you're a plumber, electrician, or general contractor, virtually everything you invoice for falls into this category — and you can claim ITCs on your related business purchases.

Zero-rated. These sales are still treated as taxable under the law, just taxed at a rate of 0% — so no GST gets added to the customer's bill. The list is specific: things like basic groceries, prescription drugs, most agricultural and fishing products, and goods exported outside Canada. Very few trades businesses deal in zero-rated sales day to day, but it's worth knowing the category exists, especially if any part of your work involves exports or agricultural equipment. Because these sales are still legally "taxable," just at 0%, you can still claim ITCs on the purchases related to them.

Exempt. These sales aren't taxed at all — but here's the part people miss: exempt is not the same as zero-rated. Exempt sales include things like most residential rent, most health and dental care services, and most financial services. The key difference: if what you sell is exempt, you can't claim ITCs on the purchases related to it either. You're simply outside the GST system for that part of your business — no charging it, no claiming it back.

For the large majority of trades and contracting businesses, this distinction is mostly academic — nearly everything you sell is standard and taxable, full stop. But if any part of your business touches something outside typical contracting work, it's worth checking which category it falls into, because it changes both what you charge and what you can get back.

So: When Do You Actually Need to Register?

Once you know your sales are taxable (or zero-rated), the next question is whether you're required to register. In short: once your total taxable revenue — including zero-rated sales — crosses $30,000 over four consecutive calendar quarters, you're required to register. There's also the option to register voluntarily before you hit that threshold. We've written a full breakdown of those rules, including the rolling four-quarter calculation and the rule for anyone running more than one business, here: When Do You Have to Register for GST.

What Registering Actually Means for You

Registering isn't just a compliance box to check — it changes how your business operates in two directions at once.

On the way out: once you're registered, you have to start charging GST on your taxable sales, and you become responsible for collecting and remitting it to the CRA on a set schedule. How often you file depends on your revenue — we've covered that in detail here: How Often Do You Have to File Your GST Return.

On the way in: registering also means you can start claiming ITCs — getting back the GST you paid on your own business purchases, from materials and tools to fuel and equipment. For a lot of new businesses, this is the upside that gets overlooked: registration isn't only an added obligation, it's also a way to stop losing money on GST you're already paying. We've covered exactly what documentation you need to claim ITCs here: What Is an Input Tax Credit.

Quick Reference

The Bottom Line

For most trades businesses, the "what am I actually selling" question resolves itself quickly — almost everything you sell is standard and taxable. But it's worth actually confirming that, rather than assuming it, especially if any part of your work touches exports, agricultural products, or anything outside standard contracting services. Once you know what you're selling, the registration threshold and filing questions become much more straightforward.

This article is for general informational purposes only and does not constitute legal or tax advice. For guidance specific to your situation, consult a CPA or Canadian tax professional.