You can locate and edit this reminder by going to My Account (top right corner) > Notification Templates > click to edit Invoice Reminder.
**Note: The replacement tags in the invoice reminder template will automatically fill in all the pertinent invoice information when the reminder is sent to the client.**
Important: This invoice notification template is used ONLY for the invoices generated automatically based on client agreements with automated invoicing, where you check the option to send invoice reminders in the Invoicing tab of the agreement wizard. The template is not used for invoices outside this type of client agreements (like the product invoices, the manual invoices based on agreements, or the invoices created with the "Add Miscellaneous" button in Billing menu > Invoices > button '+Create').
To send a reminder for the latter types of invoices, you can either go to the client's Invoices file: Contacts > Contact Name > scroll down to the 'Invoices' section on the right side > click the link 'View all' > and use the 'Re-send' option in the drop-down menu to the right of the respective invoice(s).
Or, alternatively, you can send a direct email to remind the client about the unpaid invoice(s).