As per CRA:
If you do not receive your payment on the scheduled day, wait 10 working days before calling. You can view your GST/HST payment dates and amounts in My Account.
A change in your situation may cause your GST/HST credit payment to be recalculated based on the effective date of the change. The CRA will send you a GST/HST credit notice of redetermination showing the revised annual credit amount when any of the following situations apply and change the amount of your payment:
- after each reassessment of either your or your spouse or common-law partner's tax return that affects net income
- after a change in your marital status
- after a change in the number of eligible children in your care
- after the death of a GST/HST credit recipient
If this does not apply to you, you can contact CRA on 1-800-387-1193 and they will assist you.
