The short answer: once your total worldwide taxable revenues exceed $30,000 in any single calendar quarter, or over four consecutive quarters. At that point, you're legally required to register for a GST/HST number — you're no longer a "small supplier."
But there's more nuance to it. Let's break down exactly when, how, and what changes once you register.
CRA uses two tests. You're required to register if either of these applies:
Example: You earned $8,000/quarter for most of 2025. By Q4, your rolling 4-quarter total hits $32,000. You've crossed the threshold — you must register within 29 days and start collecting HST from the next invoice.
Once you cross the threshold, you have 29 days to register. After registration, you must charge and remit HST on all future invoices.
Taxable revenues include almost all your self-employment income:
What does NOT count:
Important: The $30,000 threshold is based on revenue, not profit. Even if your business isn't profitable yet, if you've invoiced $30,000+ you need to register.
Voluntary registration is allowed — and sometimes makes sense:
Reasons to register early:
Reasons to wait:
Registration is free and takes about 15 minutes online:
Choose annual filing if your revenues are under $1.5M. It means one filing per year instead of four — much simpler.
| Before Registration | After Registration |
|---|---|
| No HST on invoices | Must add HST to all invoices |
| No ITCs claimable | Can claim HST paid on expenses back |
| No HST filing | Annual (or quarterly) HST return required |
| Simpler bookkeeping | Need to track HST collected and ITCs separately |
Once registered, you can choose how to calculate what you owe:
Regular Method: Remit (HST collected − ITCs claimed). More accurate, more work.
Quick Method: Multiply your total revenue (incl. HST) by a flat rate. In Ontario, that's 8.8% for most service-based freelancers. You keep the difference as a "Quick Method benefit."
Quick Method Example: You invoice $100,000 + $13,000 HST = $113,000 collected. Quick Method remittance: $113,000 × 8.8% = $9,944. You keep $3,056 of the HST you collected. That's roughly $3K of free money if your expenses are low.
Quick Method is better when your ITCs (expenses with HST) are low relative to your revenue. If you have high business expenses, regular method may give you a bigger refund.
Once you register, every invoice needs a line for HST, and every expense needs an ITC column. If you're doing this manually in a spreadsheet, it's manageable — but the spreadsheet needs to be set up right from the start.
You need to track:
Tracks HST collected + ITCs automatically. Compares Quick Method vs. Regular Method. Generates your CRA filing summary. Ontario rates pre-loaded (all provinces configurable).
Get the HST/GST Tracker — $15No. You only charge HST from the effective date of your registration. Any invoices sent before registration don't need HST added retroactively.
Generally no — services exported outside Canada are "zero-rated" for HST purposes. You don't charge HST to foreign clients, but you can still claim ITCs on your Canadian expenses.
CRA can assess HST on all revenues from the date you should have registered, plus interest and penalties. It's not catastrophic, but it's an avoidable headache.
The same $30,000 threshold applies to corporations. Your corporation's revenues count, not your personal income.