The border is still a customs border
It is easy to think of Canada as almost domestic. It isn’t. A shipment from the US to Canada is a full international export and clears Canadian customs like any other, so it needs a proper declaration of what is inside and what it is worth.
The Canada Border Services Agency (CBSA) assesses duty and taxes when the shipment arrives: GST, plus PST or HST depending on the province. Those rates are set by the federal and provincial governments, not by the carrier or by us.
Goods that qualify under the USMCA rules of origin can come in with reduced or no duty, but only if they are declared correctly. Our customs duty guide explains how duty is generally worked out.
