To get an Ontario HST number, open a federal CRA GST/HST account: Ontario does not issue a separate HST number, so you register for an HST number in Ontario through the same GST/HST registration process used in Ontario and other provinces outside Quebec (Quebec businesses register through Revenu Québec instead). Register only after determining whether registration is required or voluntary and choosing the correct effective date.
How to apply for an HST number in Ontario
Register online through Business Registration Online (BRO) — the CRA’s fastest way to get a Business Number (BN) and a GST/HST account together:
- Sign in to your CRA account, or create one. If you have not filed a return in the last two years, you may not be able to register for a CRA account until you file.
- On the Welcome page, select “+ Add account,” then “Business account,” and choose to register a business.
- Select the GST/HST program account and enter your business details, including the effective date of registration.
- Submit the application; save or print the BN and GST/HST account number shown on screen.
If BRO does not fit your case — for example, registering a business owned by another business, or registering when an owner or director is deceased — apply instead with Form RC1 by mail to your tax centre. If your GST/HST account was closed and the business has not changed, contact the CRA about reopening it instead. The CRA mails the BN and/or program account number, depending on what you requested; processing and mailing can take 30 days or more.
Do you need to register?
If you make taxable supplies in Canada, you must register once your worldwide taxable supplies, together with those of any associated persons, exceed $30,000 in a single calendar quarter (special rules apply to some businesses) — your registration takes effect no later than the day of the supply that crosses the threshold, and you must apply within 29 days of that effective date. If you exceed $30,000 over your last four consecutive quarters but not in any one quarter, you generally stop qualifying as a small supplier at the end of the following month, so your registration takes effect no later than your first supply after that, and you must apply within 29 days of that effective date. If your taxable supplies do not exceed $30,000 in any single quarter or over the last four consecutive quarters, you are generally a small supplier and may register voluntarily, subject to exceptions. See the full small-supplier threshold rules for how the CRA counts revenue and sets the effective date, or whether voluntary registration fits a smaller business.
Temporary SIN route
If you have a temporary Social Insurance Number (SIN) that starts with 9 and are a business owner, director, partner, or trustee, the CRA says you must use Business Registration Online (BRO) to register for a BN and most CRA program accounts, including a GST/HST account. Use the CRA’s separate-process list only for a program account that cannot be registered through BRO.
Prepare and retain
Have legal and operating names, structure, BN (if any), fiscal year-end, expected taxable sales, effective date and relevant person details ready. Save or print the BN and GST/HST account number shown in BRO; the CRA says the BN will not be sent to you afterward.
Is an HST number the same as a business number?
No. Your Business Number (BN) is the 9-digit identifier the CRA assigns once; your GST/HST (HST) number is that same BN plus a program identifier and a 4-digit reference. RT marks a GST/HST account, while RC marks a corporation income-tax account and RP a payroll account — the same BN can carry several of these program accounts at once. See CRA Business Number: BN and program accounts explained for the full list.
| Part | Example | What it is |
|---|---|---|
| Business Number | 123456789 | 9-digit CRA identifier for the business |
| Program identifier | RT | GST/HST account (RC = corporate income tax, RP = payroll) |
| Reference number | 0001 | 4-digit reference for this specific account |
Example only — not a real business number.
How to find your HST number
If you already registered, your GST/HST account number is shown on screen during your BRO session, in your CRA My Business Account under the GST/HST (RT) program account, or on the CRA notice if you registered by mail with Form RC1. To check a supplier’s HST number instead of your own, use the GST Registry search.
After you get the number
Once registered, charge the 13% HST on taxable supplies made in Ontario (zero-rated supplies are taxed at 0%), show the GST/HST number on invoices and receipts of $100 or more, and file a GST/HST return for each reporting period and remit any net tax owing. Use the Ontario Sales Tax Calculator to check the HST on an invoice.