Currently, the system does not allow a review of payers along with their current balance and information whether an invoice has been issued for the current period. The lack of such a possibility requires the person issuing the invoice to be very careful and “manually” to check which payers the invoice has been issued and which have not (I am thinking here of payers who are issued invoices paid by bank transfer periodically, e.g. monthly). Request to add functionality that will show the balance of a given payer for the period and information about the issued invoice (e.g. info on the last invoice issued).