what is qst
GST/HST and QST. In Quebec, quÃ©bec the goods and services (TAX) gst and The quebec quÃ©bec (SALES) tax qst are collected on sales (Or supplies this link will open a) new window of most property. and servicesnce you are registered for the GST and QST, you are required to. 1  collect the taxes from your clients. 2  calculate any input tax credits and input tax refunds you may be entitled to.