A GST/HST registration number is a unique identifier issued by the Canada Revenue Agency (CRA) that allows a business to collect, remit, and report Goods and Services Tax (GST) or Harmonized Sales Tax (HST).
It forms part of your 15-character Business Number (BN) and is required for most small businesses operating in Canada that sell taxable goods or services.
Structure of a GST/HST Number
A standard GST/HST registration number looks like this:
123456789 RT0001
- 123456789: the Business Number (BN)
- RT: identifies the GST/HST account number
- 0001: the reference number for that specific account
This structure helps the CRA connect your GST/HST account to other related tax accounts such as payroll, corporate income tax, or import/export.
Who Needs To Register
You must register for a
GST number if your business earns more than
$30,000 in total taxable revenue over four consecutive calendar quarters.
You are required to register if you:
- Sell taxable goods or services in Canada
- Earn more than $30,000 in annual revenue in any 12-month period
- Operate as a freelancer, contractor, or self-employed professional serving Canadian clients
- Import or sell goods and services online to Canadian customers
Businesses below the $30,000 threshold are considered small suppliers, and registration is optional. However, voluntary registration allows business owners to claim Input Tax Credits (ITCs) on eligible business expenses, which can improve cash flow and reduce net taxes payable.
Some supplies, such as most financial and health services, remain GST/HST-exempt regardless of registration status.
GST vs. HST vs. PST
Sales tax in Canada varies by province:
- Ontario – HST (13%)
- Nova Scotia, New Brunswick, Newfoundland and Labrador, Prince Edward Island – HST (15%)
- Alberta – GST only (5%)
- British Columbia, Saskatchewan, Manitoba – separate Provincial Sales Tax (PST) plus 5% GST
- Quebec – Quebec Sales Tax (QST) administered by Revenu Québec
Understanding your province’s rules is critical before registering for a GST/HST account, as filing and remittance processes differ depending on where you do business.
How To Register for a GST/HST Number
There are three ways to register with the CRA: online, by phone, or by mail.
1. Register Online
The fastest and most common method is through the CRA’s Business Registration Online (BRO) portal.
Steps:
- Visit the CRA Business Registration Online page.
- Sign in using your My Business Account, or create one.
- Enter your Business Number (BN) or apply for one if you don’t have it.
- Select the option to register for a GST/HST account.
- Provide your business start date, type of business, and estimated annual revenue.
- Review and confirm the information before submitting.
Your GST/HST registration number is issued immediately online and will also be mailed to you for your records.
2. Register by Phone
Call the CRA’s Business Enquiries line at 1-800-959-5525 to register by phone.
Be ready to provide your legal business name, structure (sole proprietorship, partnership, or corporation), start date, and expected sales.
3. Register by Mail or Fax
If you prefer paper registration, complete Form RC1 – Request for a Business Number (BN) and send it to your regional tax office by mail or fax.
Processing typically takes two to four weeks.
After Registration
Once you receive your GST/HST number, you must:
- Charge GST or HST on taxable sales based on your province’s rate
- File GST/HST returns monthly, quarterly, or annually depending on your revenue
- Remit collected tax to the CRA by the assigned deadline
- Display your GST/HST number on all invoices and receipts
- Maintain accurate records of business expenses and sales for at least six years
Failing to remit collected taxes or missing filing deadlines can result in penalties and interest from the CRA.
Setting up proper tracking in QuickBooks Online, Xero, or other accounting software ensures that every General Sales Tax transaction is recorded correctly.
Verifying a GST/HST Number
You can confirm if a business is properly registered using the GST/HST Registry available on the CRA’s website.
This online tool lets you verify whether a business’s GST/HST number is valid and active — a useful step before entering contracts or claiming ITCs.
Key Takeaways
- A GST/HST registration number is required for most Canadian businesses once annual revenue exceeds $30,000.
- Registration can be completed online, by phone, or by mail through the CRA.
- Once registered, you must collect, remit, and report GST/HST on taxable sales.
- Knowing your province’s rules (GST, HST, PST, or QST) helps ensure full tax compliance.
- Use the CRA’s GST/HST Registry to confirm registration details for your business or vendors.