For the third year in a row, the Quebec Sales Tax (QST) will be changing. Fortunately, the change is not to the rate, which effectively remains the same, but rather an effort to harmonize the QST with the GST. Consequently, the most significant change is the method by which the rate is calculated.
In the past, the QST used to be calculated on the total sale plus GST. As a result the published rate was 9.5% while the effective rate was actually 9.975%. The harmonization of the GST and the QST requires that the QST be charged on the sale amount only, without the GST. As such the published rate and the effective rate will both be 9.975%. This is illustrated below: