Do I need a business number to sell online in Canada?

What actually triggers the need for a business number

A business number is a nine-digit identifier the CRA uses to track a business across several program accounts. These include GST/HST, payroll, corporate income tax, and import/export. It is not required simply to start a sole proprietorship or open an online store. Many small sellers operate for months, sometimes longer, filing their business income on a personal T1 return with a T2125 schedule, using their own SIN. They carry no business number at all.

The number becomes necessary the moment one of a few specific things happens. You register for GST/HST. You hire an employee and need a payroll account. You incorporate and need a corporate tax account. Or you start importing goods regularly and need an import/export account. Each of these gets a program account (RT for GST/HST, RP for payroll, RC for corporate tax, RM for import/export) attached to the same underlying business number. Registering for any one of them generates the number if you do not already have it.

How a sole proprietor files without one

Before any of those triggers apply, a sole proprietor selling online reports business income and expenses on Form T2125. This is filed as part of their personal T1 return under their own SIN. There is no separate business tax return and no separate filing deadline distinct from your personal return deadline. This is the simplest possible structure, and it is entirely legitimate to operate this way indefinitely for a small store that never crosses the thresholds that require registration.

Where sellers sometimes get confused is assuming a business number is needed to open a business bank account or a payment processor like Stripe or PayPal. Many banks and processors accept a sole proprietorship account without a business number, particularly if the store operates under the owner's own legal name. Requirements vary by institution, though, so it is worth checking directly with the bank or processor you plan to use.

Registering an Ontario business name if you operate under one

Your online store might operate under a name other than your legal name, for example a brand name. If so, Ontario generally requires registering that business name with the province, rather than using your personal name. This is a separate step from getting a CRA business number. It is a provincial registration that confirms the name is associated with you, and makes it legally usable for contracts, invoicing, and opening accounts in that name. A sole proprietor using a business name still files taxes under their own SIN unless a business-number trigger also applies.

When GST/HST registration pulls in a business number

Once your worldwide taxable sales pass the $30,000 small supplier threshold over four consecutive calendar quarters, GST/HST registration becomes mandatory. That registration is what generates your business number if you do not already have one, along with the RT program account attached to it. This is covered in more detail in when do I have to register for GST/HST. Some sellers register voluntarily before hitting that threshold to start claiming input tax credits on startup costs. This also triggers the business number earlier than it would otherwise be needed.

Why importers often need one sooner than other sellers

A seller who imports inventory needs an RM import/export account to clear goods through the Canada Border Services Agency. This applies whether the seller imports regularly, rather than buying entirely from Canadian suppliers or dropshipping through a supplier that handles importing. This account is held in the business's own name. The need for it holds whether or not GST/HST registration has happened yet, since customs clearance and GST/HST registration are governed by separate rules. An active online seller who imports product directly often ends up needing a business number for this reason, well before crossing the small supplier threshold.

Incorporating changes the answer immediately

The moment you incorporate, a business number is required. A corporation is a distinct legal entity from its owner and needs its own RC corporate tax account to file a T2 return. There is no sole-proprietor-style option to file corporate income under a personal SIN. If incorporation is on your radar for tax-rate reasons as sales grow, the business number question resolves itself at that point, regardless of GST/HST or import activity. We compare that further in sole proprietorship or corporation: how the taxes compare.

Getting the number itself once you need it

Registering for any one of the triggering accounts generates the business number automatically as part of that registration. These accounts include GST/HST, payroll, import/export, and incorporation. There is no separate standalone application most sellers need to file first. The registration can generally be completed online, and the number itself typically arrives quickly, often the same day for an online GST/HST or import/export registration. Incorporation paperwork, though, can take longer to process, depending on the method used.

Once you have a business number for any one program account, adding a second account later reuses the same underlying number rather than issuing a new one. For example, registering for payroll after already having a GST/HST account does not generate a second number. There is no need to worry about ending up with multiple conflicting business numbers as the business grows and adds activities.

How we help sellers get this right

We review a new online seller's actual activity, sales volume, import plans, and whether incorporation makes sense. We then register only the accounts that are actually needed, rather than defaulting to full registration on day one. Our business incorporation and compliance page covers registration for sole proprietors, business names, and incorporated businesses alike.