If you are a registrant, you must file a GST/HST and a QST return for each reporting period, even if you are not entitled to a refund or have no amount payable.

Because the GST and QST are both administered by Revenu Québec, you can file a combined GST/HST-QST return.

Some businesses and organizations can apply to have their branches or divisions file separate GST/HST and GST returns. To do so, they must use form FP‑2010-V, Application or Revocation of Application to File Separate Returns or Rebate Applications.

You must calculate the following for each reporting period:

• the GST and QST you collected and the GST and QST you were required to collect (that is, tax billed but not paid) during the reporting period; and
• the GST and QST you paid or were required to pay that entitle you to input tax credits (ITCs) and input tax refunds (ITRs).

If the difference between the results of these two calculations is positive, this is the net tax you must remit to us.

If the difference is negative, this is your refund.

Whether you have an amount payable or a refund, you must take any adjustment you've made into account no later than the filing deadline for the return.

To determine the GST and QST payable, use two columns in your sales book to enter the GST and QST that you billed on taxable sales (excluding zero-rated sales) for the reporting period concerned, and two columns in your purchase book to enter the GST and QST that were billed to you during the same reporting period and that entitle you to ITCs and ITRs.

Since the taxes may be included in the total price, it is important that your method allows you to identify the tax amounts.

See When to Collect GST and QST to find out when tax is considered paid and when it is considered due in the case of leases, vending machines, partial payments and conditional sales.

In addition, when calculating net tax on your return for a given period, you must take into account all ITCs and ITRs claimed for the period, including those applicable to previous periods. You may also take into account any amounts that, further to an adjustment, can be deducted in the calculation of your net tax for the period. These amounts generally correspond to the GST and QST you paid or were required to pay.