GST/HST for Ontario businesses
A plain-English overview of how GST/HST registration, charging, and filing works in Ontario.
What GST/HST is
In Ontario, most goods and services are subject to the Harmonized Sales Tax (HST), which combines the federal GST and Ontario's provincial component into a single tax.
The small supplier concept
The CRA uses a "small supplier" threshold to decide when GST/HST registration becomes mandatory. Below the threshold, registration is generally optional; above it, registration is generally required. Confirm the current threshold with the CRA — this number changes and applies over rolling periods.
Voluntary registration
Many businesses register voluntarily even before they cross the threshold — for example, to claim input tax credits (ITCs) on business purchases, or to appear established to larger clients.
Charging HST
Once registered, you charge HST on taxable supplies of goods and services made in Ontario. Certain supplies are zero-rated or exempt — the CRA publishes the specifics.
Input tax credits (ITCs)
Registrants can generally claim ITCs to recover the GST/HST they pay on eligible business inputs. This is one of the practical reasons to register.
Filing and remitting
Filing frequency (monthly, quarterly, annual) depends on your revenue and elections. You report HST collected, claim ITCs, and remit the difference (or receive a refund).
Records
Keep detailed records of your sales, taxable status, and ITC-supporting invoices. The CRA can audit HST accounts.