Sending Payment Reminders from the Clients view
First, select a client and then select View. Next, select the Finances option on the left hand side, and then select the Invoices tab. Finally, select an invoice with the status Unpaid, and then select Send Payment Reminder from the banner at the top.
Sending Payment Reminders from the Workflow view
Select Workflow, and then select Unpaid under Billing. Next, select an unpaid invoice, and then select Send Payment Reminder.
Both methods will produce an invoice to send to the client. By selecting Send Email, your client will then receive an email reminding them of their outstanding payment, along with the associated invoice.