As of January 1st, 2013, the Quebec Sales Tax (QST) rate will increase from 9.5% to 9.975% and businesses will need to modify their check-out systems in order to stop charging QST over the Goods and Services Tax (GST).

Certain retailers' computer systems are not currently able to process transactions with 3 decimal points. Certain cash register systems are configured to calculate sales tax rates with up to two decimals and cannot apply a three decimal QST rate.

However, it is always possible for a retailer to use mathematical factors that are rounded off to two decimals when the cash register system used does not allow determining the QST based on the actual three decimal rate (section 69.3.1, An Act respecting the Québec sales tax, RSQ, c T-0.1).

Retailers looking for further details on the latest QST calculation method can visit the following Revenue Quebec web pages:

Changes to the QST System in 2013
Calculating the Taxes