Self-employed individuals such as drivers can receive a refund equivalent to the amount of QST/GST paid on their expenses related to their activity (such as vehicle maintenance or gasoline). With the quick accounting method, this refund takes the form of an additional automatic weekly payment of 6.0864%, calculated based on the rates provided for in the agreement between Revenu Québec and Uber. In other words, of the 14.975% of combined GST/QST you charge on your ridesharing fares, 8.8886% is remitted to Revenu Québec on your behalf and 6.0864% is paid to you.
Note that under the quick accounting method, you cannot claim GST and QST credits individually for the tax paid on your operating expenses (such as vehicle maintenance), as the 6.0864% refund replaces those individual credits. However, you may be eligible for such a credit on capital expenses (Ex. the purchase a vehicle).