After Invoice has been posted. The entries can only be reversed via a return order.

1. Go to Search → Sales Return Orders and create a new return order.
   
   
   
2. Fill in Sell-to Customer No.
   
   
   
3. On the Actions ribbon, use the Get Posted Document Lines to Reverse Function
   
   
   
4. In the Pop-up page, find the records to return using the Find or Filter
   
   
   
5. Fill in the field Return Qty. to Recieve
   
   
   
   
6. Post the receipt