As a registrant, you have to charge GST/HST on taxable goods and services you make to:
You have to charge GST/HST whether they make purchases for themselves or their organizations.
Note
Foreign representatives are not exempt from paying GST/HST. You must collect the GST/HST from them, even if they show you a diplomatic identification card.
However, they may be eligible to apply for a GST/HST rebate if you give them acceptable documentation for their purchases. To verify which information is needed to apply for a rebate, see Invoice requirements.
To claim the rebate, they have to complete and file Form GST498, GST/HST Rebate Application for Foreign Representatives, Diplomatic Missions, Consular Posts, International Organizations, or Visiting Forces Units.