Add Automatic Reminders to Invoices Online
Enable automatic reminders for your customers when an invoice due date is approaching or past due.
During the invoice creation process, scroll to More Options > check Schedule payment reminders for this invoice. By default, a reminder will be automatically sent 1 and 3 days after the due date.
To set custom reminders, click Edit Reminders.
Edit the two default options and/or click Add Reminder to add another option.
Learn more about Square Invoices notification settings.