Add Automatic Reminders to Invoices Online
Enable automatic reminders for your customers when an invoice due date is approaching or overdue.
During the invoice creation process, scroll to More Options > tick 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.