Prerequisites
Before you can check if your customer has viewed an invoice, you will have to:
To see the invoices that your customers viewed:
The Eye icon will be displayed next to the invoice number in the invoice list page if your customer viewed the invoice from their portal. If your customer opens the email that you sent, the Open Mail icon will be displayed next to the invoice number in the invoices list page.
Books
Simplify accounting
and GST filing.