A form of sales tax applied to purchases in some Canadian provinces. Some provinces charge their Provincial Sales Tax (PST) as a "value added tax" while others use a "cascading tax." Value added taxes are calculated on the value of the item being bought without taking the Goods and Services Tax (GST) into account. Cascading taxes are calculated after the GST has been applied, effectively applying a tax on top of a tax. Some provinces have done away with a PST and have moved towards a Harmonized Sales Tax (HST) which combines the GST and the PST.