If required, a payment reminder can also be printed from a summary invoice with the Payment Reminder button on the ribbon. 

A payment demand of a summary invoice can be printed at any time, regardless of the due dates of the summary invoice or the normal invoices attached to it. It can be printed to PDF or printer, or sent as an email attachment.

However, adding a reminder fee or delay interest is not possible without customizing the summary invoice template. 

To avoid sending by accident a payment reminder of an invoice belonging to a summary invoice, the software informs if a payment reminder is being created for an individual invoice which belongs to an open summary invoice.  A similar warning is displayed when a payment reminder is being printed for multiple invoices of which some are on a summary invoice. However, the software does not inform which of the selected invoices belong to a summary invoice.