When to register for HST in Ontario

Updated September 28, 2026

Ontario's harmonized sales tax (HST) is 13%. You charge it on most sales once you're registered, and you send it to the Canada Revenue Agency (CRA).

When you must register

You're a "small supplier" and don't have to register while your taxable sales stay at $30,000 or less. Once you go over $30,000 in a single calendar quarter, or over the last four calendar quarters combined, you must register.

Why register early

• Registered businesses can claim back the HST they pay on business purchases (input tax credits), including startup costs like equipment and supplies.
• Some business customers expect to see an HST number on your invoices.

Why wait

• If you sell mostly to consumers, adding 13% raises your prices.
• You'll have to file HST returns even in slow periods.

How

Register online with CRA using your business number. Keep every receipt from day one so you can claim what you're entitled to.

General information, not tax advice.

Official sources

• CRA: GST/HST for businesses