The promotion code application process varies by country/region. If your referral is in the United States, Canada, or the EMEA region, they should apply your promotion code during the Google Workspace sign up process, when providing their billing information. The code must be entered when prompted for their payment information, in the "Promotion Code" field, before they checkout. If your referral is in Argentina, Brazil, Chile, Colombia, Mexico, Peru or APAC region, they are able to enter their promotion code at any time during their 14-day trial when selecting their Google Workspace, as long as they have not yet entered their billing information. This can be done in the Billing section of their Admin Console.