Note: Invoice reminders will only be sent if you have enabled them under Settings > Invoices.
- Navigate to the Users screen (click on Teams if you're searching for a team)
- Locate the user or team for which you want to add an invoice contact
- From the side panel, click in to 'Account'
- Click 'Edit'
- Scroll down to 'Billing details'
- Enter the email address under 'Additional email'
Once this is done, any invoices associated with the relevant user or team will be sent to this email address as well as the user or team admin. In addition these details will show up on the user or team's invoice.