HST on a private used-car sale in Ontario: what you’ll actually pay
Written by Ontario VIN Check Editorial TeamReviewed by Ontario VIN Check Content Review TeamLast updated: August 1, 2026
One of the most common surprises for Ontario used-car buyers is the tax bill at registration. A private seller doesn’t charge you HST — but the province still collects tax when you plate the car, and it isn’t always calculated on the price you paid. Here’s how it works so nothing catches you off guard.
Private sale vs dealer: two different tax stories
Buy from a registered dealer and you pay 13% HST on the agreed price, the way you would on most goods. Buy privately and there’s no HST from the seller — instead you pay 13% Retail Sales Tax (RST) directly to the province when you register the vehicle at ServiceOntario. Same rate, different mechanism, and one important twist below.
The “greater of” rule
On a private sale, RST is charged on the greaterof the purchase price or the vehicle’s wholesale value — the Canadian Red Book value the province uses as a reference. This exists to stop buyers and sellers from writing an artificially low price on the bill of sale to dodge tax. In practice: if you pay more than the Red Book value, you’re taxed on your price; if you pay less, you’re taxed on the Red Book value anyway. The UVIP shows the wholesale value the province will reference, so you can see it before you go to register.
When you genuinely paid less than book value
Sometimes a car really is worth less than the Red Book figure — high mileage, mechanical issues, cosmetic damage. In that case, an appraisal from a qualified appraiser (or, for gifts and certain family transfers, the specific exemptions that apply) can let the tax be based on the appraised value instead of the book value. If your car is a rough example of its model, an appraisal can be worth far more than it costs.
Estimate before you negotiate
Because the tax rides on the greater of price or book value, it’s worth knowing the number before you agree on a price. Run the figures through our Ontario used-car HST calculator for an estimate, and read the full HST on used cars guide for the exemptions and edge cases. Knowing the tax up front keeps it in the negotiation rather than as a shock at the counter.
The bottom line
A private Ontario used-car sale has no HST from the seller, but you pay 13% RST at registration on the greater of your price or the Red Book value. Check the wholesale value on the UVIP, estimate the tax before you negotiate, and consider an appraisal if the car is genuinely worth less than the book says. Always confirm current rates and exemptions with ServiceOntario before you register.