How does GST/HST/PST work per Canadian province in Magento?

Canada has three layers of sales tax that vary by ship-to province:

• GST (5%), Federal Goods & Services Tax. Applies everywhere.
• HST (13-15%), Harmonized Sales Tax. Replaces GST + PST in Ontario (13%), Nova Scotia, New Brunswick, Newfoundland & Labrador, PEI (all 15%).
• PST, Provincial Sales Tax. Stacked on top of GST in BC (7%), Saskatchewan (6%), Manitoba (7%).
• QST (9.975%), Quebec Sales Tax. Stacked on top of GST in Quebec for an effective 14.975%.
• Alberta & Territories, GST 5% only, no provincial layer.

In Magento we configure tax classes per product type, tax rules per ship-to province, and the point-of-supply rules (which determine which province’s rate applies). For multi-province stores we wire Vertex, Avalara, or TaxJar Canada so rates auto-update if the government changes them.