Most of the small & medium size organizations still demand advance monies from customers to manage the working capital as the credit periods still vary from 30-90 days period.  To show the true figures & facts, advances to be received should be reflected in receivables and advances to be paid to be reflected in payables and these are non-item/non-stock transactions.  Currenlty Zoho Books has a place holder for the advances once they are paid or received as available credits and they can be consumed once the monies received or paid against the actual invoices.  However this doesn't solve the issue of reflecting true figures of receivables / payables contractually.  Are there any alternative transaction types such as Debit Notes (advance receivable) or Credit Notes (Advance Payable) without touching the stock ?