Do you have to register for PST or QST when you sell into another province?

Canada runs three sales-tax systems, and your registration covers only one of them

The reason this question has no single answer is that Canada does not have one sales tax; it has three families, and an Ontario business meets each of them differently. The first family is the harmonized provinces: Ontario, New Brunswick, Nova Scotia, Prince Edward Island and Newfoundland and Labrador, where the provincial tax is folded into HST and administered by CRA. The second is the GST-only jurisdictions, Alberta and the three territories, where the federal 5 per cent is the whole story. The third is the provinces that kept a separate provincial tax: British Columbia, Saskatchewan and Manitoba with their retail sales taxes, and Quebec with QST, which is closely modelled on GST but administered by Revenu Québec.

Your existing GST/HST number belongs to the federal system, and the federal system reaches the first two families completely. Selling into Nova Scotia or Alberta from Mississauga changes the rate on the invoice and nothing else: one registration, one return, one remittance. The third family is where the registration question is real, because BC, Saskatchewan, Manitoba and Quebec each keep their own register, their own returns and their own view of when an out-of-province seller has to sign up.

So the first step is a sort, not a calculation. List the provinces your customers are in, mark which family each belongs to, and set the HST and GST-only provinces aside as a rate issue. Whatever remains is the list you actually need to test.

Place of supply decides the rate, and it follows the customer more than you

Which province's tax applies to a sale is decided by place-of-supply rules, and for most owner-managed businesses the answer leans toward the customer's location rather than yours. For goods, the supply is generally made in the province where the goods are delivered or made available to the buyer, so a shipment from your Ontario warehouse to a Winnipeg address is a Manitoba supply for provincial purposes and a GST-only supply for federal purposes. For most services, the rules look to the customer's address that you obtained in the ordinary course of business, with special rules for services tied to real property, events and a few other categories. For intangibles such as software licences, subscriptions and digital content, the rules look at where the rights can be used and, where that is unrestricted, at the customer's address.

The provincial systems apply similar logic in their own words. A retail sales tax province generally treats goods delivered into the province as taxable there, and each of the three has expanded its rules over the years to reach software, telecommunication services and certain other services delivered to its residents. Quebec's QST place-of-supply rules mirror the GST rules almost exactly, which is convenient, because a sale that is a Quebec supply for GST is almost always a Quebec supply for QST.

Two practical consequences follow. Your invoicing system needs to know the delivery or customer province for every sale, not just the billing address, because that is the field the rate hangs on. And the province of supply for a sale into BC, Saskatchewan, Manitoba or Quebec is what makes the registration question live; a supply that is made in Ontario under these rules never triggers a western registration no matter where the buyer's head office is.

HST is a rate question; PST and QST are registration questions

The distinction owners most often miss is that the same word, "register", means something different across the families. For HST there is nothing to register: you are already in, and the destination province's rate applies automatically because the harmonized provinces agreed to let the federal system collect for them. For the retail sales tax provinces and Quebec, nothing about your federal account reaches them. If their rules require you to register, that means a separate application, a separate account number, separate returns on their own filing frequency, and separate remittances to a provincial ministry or to Revenu Québec.

Quebec sits between the two camps. Its QST has the same base and the same recoverable logic as GST, so a business registered under the general QST system recovers QST on its Quebec inputs as an input tax refund, the same way HST comes back as an input tax credit. But it is still a second registration with a second administrator, and Quebec also runs a simplified registration stream for out-of-province sellers to Quebec consumers that collects tax without giving those refunds. Which stream you land in depends on whether you carry on business in Quebec or merely sell to people there, and the difference matters to your margins.

When a province can require you to register: carrying on business, and the remote-seller rules

Each provincial system has two doors, and you only need to walk through one of them to be required to register. The first door is the traditional one: carrying on business in the province. Having premises, inventory, employees, agents or equipment there, soliciting orders through a representative there, or delivering goods with your own vehicles into the province are the kinds of facts that have always brought a seller inside a province's sales tax. If you have a permanent establishment in a province for corporate tax purposes, assume you are carrying on business there for sales tax purposes as well; the reverse is not true, because the sales-tax test is looser.

The second door is newer and catches sellers with no physical presence at all. British Columbia, Saskatchewan, Manitoba and Quebec have each extended registration to out-of-province sellers who sell taxable goods, software or services into the province, and each sets its own threshold and its own definition of which sales count. The mechanism is the same everywhere: the province measures your sales to its residents over a look-back period, and once you pass its line you must register, charge its tax and file its returns even though you have never set foot there. The thresholds differ by province and by what is sold, some apply only to consumer sales, and they have been amended more than once, so we check the current figures against each province's rules before advising, rather than quoting a number that may have moved.

Below the thresholds, an unregistered seller does not charge the provincial tax, and the obligation flips to the buyer, who is supposed to self-assess it. Business buyers in the retail sales tax provinces are used to this; consumers rarely do it, which is exactly why the remote-seller rules were written. The practical point for you is that being under a threshold is not a permanent state, it is a number that moves every quarter with your sales, and the moment it crosses is the moment the registration clock starts.

Registration is also sometimes worth doing before you must. A business that will have meaningful Quebec input costs, for example, can prefer general QST registration because it turns QST paid on Quebec expenses into a refund. In the retail sales tax provinces, registration also lets you buy inventory for resale exempt, using your own PST number, instead of paying PST to your suppliers with no way to recover it.

Why PST feels different from HST on the invoice and in the books

The biggest operational difference is that PST is a cost that stops with the last business in the chain, while HST and QST flow through. When you pay HST on an Ontario expense, you claim it back as an input tax credit and it never touches your margins. When you pay PST on equipment shipped to a BC job or on software licences used by staff in Manitoba, there is no credit; the tax is simply part of the price, unless a specific exemption applies, the most common being goods bought for resale and, in some provinces, machinery used directly in manufacturing. That changes how you quote, because a fixed-price contract in a PST province needs the unrecoverable tax built into the estimate.

On the collection side, the mechanics differ too. PST is charged on a defined list of taxable goods and services rather than on everything except exempt supplies, so the same invoice can carry GST on every line and PST on only some of them. Business customers in these provinces will hand you exemption certificates or their PST numbers to buy exempt for resale, and you must keep those documents to support every sale you did not tax. And each province's return has its own frequency, its own due date and its own penalty rules, none of which line up with your GST/HST calendar.

Your systems need to carry that structure. At minimum, that means tax codes by province and by item type rather than one blended rate, a customer record that stores the ship-to province and any exemption documents, and a sales report that can show, by province and by period, the figures each registration measures you against. Invoices for QST must show your QST number alongside your GST number. Most accounting platforms can do all of this, but only if someone configures it deliberately; a default Ontario setup charges 13 per cent everywhere and leaves you over-collecting from some customers while unregistered where you should not be.

What changes the answer for your business

Whether you need a second sales-tax registration comes down to a short list of facts:

• Which provinces your supplies are made in under the place-of-supply rules, since HST and GST-only provinces are a rate issue and only BC, Saskatchewan, Manitoba and Quebec raise registration
• Whether you carry on business there, through premises, people, inventory, equipment or your own deliveries, which brings you in regardless of sales volume
• How much you sell into each of the four provinces, measured against that province's current remote-seller threshold and its definition of counted sales
• Who your customers are, because several of the remote-seller rules target consumer sales, and business buyers can often self-assess or buy exempt
• What you sell, since goods, software and specified services are treated differently from other services in each provincial regime
• How much provincial tax you pay on inputs there, which can make voluntary QST registration or a PST resale number worth having before any rule forces it

Sales tax is one of four systems a multi-province footprint touches, and the registration question here should be answered alongside corporate tax, payroll and provincial registrations rather than on its own; the full sweep is set out in what a multi-province business should review for tax compliance. If Quebec is on your list, the QST question rarely arrives alone, and what expanding into Quebec adds to your corporate filings lays out the rest of the package. And if the reason you are selling into a province is that you now have someone working there, what changes for payroll when you hire in another province is the companion question.

In practice we handle this inside End-to-End Accounting: map the supplies by province, test each of the four regimes against your current numbers, register where required or where it pays, and configure the tax codes so the returns come out of the books rather than out of a spreadsheet. Where a registration was missed in earlier periods, the cheapest fix is almost always to register and file the back periods before the province writes first. A free 15-minute discovery call is enough to tell you which of the four provinces, if any, you need to worry about this year.