When you make a taxable sale (excluding a zero-rated sale), you must advise the recipient of the good or service that the sale is subject to GST and QST. You can do this by showing the amount of the taxes on the cash register receipt, invoice or sales contract, or by posting signs in your store that clearly state that the taxes are included in your prices.

Whatever means you choose, you must ensure that the GST and QST are either shown separately from the price or included in it.