HST for a new Ontario business: when to register, what to charge, what to set aside
The $30,000 threshold, what 13% does to your pricing, and the account habit that stops remittance from wiping out your month.
General information for Ontario business owners, current as of August 14, 2026. Rules, rates and thresholds change and your own facts matter — this is not legal, tax, accounting or financial advice, and reading it does not create a professional relationship. Verify against the official sources listed at the end and speak to a licensed professional before you act.
HST is the single most common thing new Ontario owners get wrong, and it is rarely because the rules are complicated. It is because tax gets spent as though it were income. Here is the shape of it.
The small-supplier threshold
You are generally a small supplier until your worldwide taxable revenues exceed $30,000 over four consecutive calendar quarters. Cross it and registration becomes mandatory — with specific timing rules about when you must start charging. Some businesses, like most taxi and ride-share drivers, must register regardless of revenue.
Registering voluntarily below the threshold
- For you: you can claim input tax credits on the HST you pay on supplies, equipment, software and subcontractors.
- Against you: you must charge 13% from your effective date, file returns on schedule, and either raise prices or absorb the tax.
- Usually worth it: capital-heavy startups and B2B sellers whose customers claim the tax back themselves.
- Usually not yet: low-cost service businesses selling to consumers who compare on sticker price.
Pricing: tax-in or tax-on-top
13% is the Ontario HST rate. If you quote $100 tax-on-top, the customer pays $113 and you keep $100. If you advertise $100 tax-in, you keep roughly $88.50 and remit the rest. Neither is wrong; what is wrong is not knowing which one your prices assume. Write it on every quote and invoice.
Filing frequency and deadlines
The CRA assigns a reporting period — annual, quarterly or monthly — based on your revenue, and you can sometimes elect to file more often. More frequent filing means smaller, more predictable payments; annual filing means one large one. Whichever you land on, put the deadline in a calendar with a reminder a week ahead, and keep every receipt you intend to claim.
What to keep
- Invoices showing your HST number and the tax charged
- supplier invoices showing tax paid
- bank and card statements
- a simple ledger that reconciles to both
The 12-month cash-flow model in our free kit has an HST holdback line built into it, so the money you owe is never counted as money you have. Rates, thresholds and filing rules change — always confirm against the CRA pages linked below, and talk to an accountant about your own numbers.
Official sources
- CRA — When to register for and start charging GST/HST
- CRA — GST/HST rates by province
- CRA — Input tax credits
- CRA — GST/HST filing and reporting periods
Rules, rates and thresholds change. Confirm against the source before you act, and speak to a lawyer or accountant about your own situation — this guide is educational and is not legal, tax or financial advice.