Invoice behaviour with POS report –

Deleting an item from an invoice – The stock line item gets returned to the inventory and the item gets removed from the POS sales report.
Deleting a credit voucher from an invoice – The customer’s credit voucher balance returns to its original balance. The credit voucher has no effect on the POS sales report.
Voiding an invoice does not trigger any change to either stock count or POS Report
Deleting an invoice does not trigger any change to either stock count or POS Report