Receipt Write-Off is used to write-off unapplied excess money lying on receipts. Suppose customer owes $100 but pays $102. So apply $100 and write-off $2. The other write-off is more like an adjustment. Suppose customer owes $100 but pays $98. The underpaid $2 can be either adjusted via a write-off or recharged to the customer using a receipt-chargeback.