The 30-second version

If your Ontario small business earns more than $30,000 over four consecutive calendar quarters, you're required to register for HST, charge 13% on most of your sales, and file regular HST returns to the CRA. That's it. The rest is detail.

When you have to register

The $30,000 threshold is rolling, not annual. The day your trailing four-quarter revenue crosses $30,000, you're considered a "small supplier" no longer, and you must register within 30 days.

You can also register voluntarily before crossing the threshold — and there are good reasons to do that, particularly if you have significant business expenses with HST you'd like to claim back as input tax credits.

What you charge

Most goods and services sold in Ontario are taxed at the 13% HST rate. Some categories are zero-rated (like basic groceries and prescription drugs) or exempt (like most healthcare services and residential rent).

If you're a healthcare practitioner — chiropractor, RMT, physiotherapist — your services are usually exempt, but specific service lines may not be. This is one of the most common areas we untangle for clinic clients.

What you file

You file an HST return periodically (monthly, quarterly, or annually depending on your revenue). The return reports total HST collected and total input tax credits claimed; you remit the difference (or claim a refund if your credits exceed your collected HST).

The four mistakes that cost the most

  1. Missing the threshold trigger. Register the moment you cross $30K rolling — you'll owe HST on anything you charged after that point even if you weren't registered.
  2. Mixing personal and business spending. You can only claim ITCs on business expenses. Mixed accounts cost you both deductions and audit-cleanliness.
  3. Filing late. Penalties are real. Set a recurring reminder, or hand it off to a bookkeeper.
  4. Not tracking ITCs properly. If you're paying HST on materials, software, professional services — that's money you can claim back. We see clients miss thousands per year.

How a bookkeeper helps

This isn't complicated work, but it's the kind of detail-heavy task that's easy to drop. Trades businesses in particular benefit from clean HST tracking because of how much HST flows through materials and subcontractor billings.

If you're past the threshold and unsure where you stand, book a free consult — we'll review your situation and tell you exactly what to do.