In order to send invoices to multiple recipients, invoices should be addressed to a contact instead of a primary carer.
⚠️ Xero users please see the note at the end of this article.
Once you have created an invoice for the Client's contact, then you can add a comma to separate the email into the other email field for the contact, as shown below. The emails should be separated by a comma e.g. email@example.com, firstname.lastname@example.org, email@example.com
Finally, go to the invoice and click on the send email button to send the invoice to multiple recipients.
⚠️ Warning for Xero users: When importing invoices to Xero, if multiple email addresses are used the import will fail. A suggested workaround for this would be to send the invoice to a contact with multiple email addresses and then edit the invoice, changing it to be directed to one recipient.