There are 2 methods to delete sale invoice, See below
NOTE : This operation can not be undo
Step 1: Go to Sales Invoice Menu & click on the down arrow beside the edit option
Step 2: Click on the delete invoice option
Step 3: Click on the Delete button to verify delete operation.
Step 1: Go to Sales Invoice page & select the checkbox before invoice number & click on the “Delete” button at bottom of page to delete selected invoices.
Step 2: Click on the “Delete” button to verify delete operation.