how can i restrict or remove items on Invoice that wasn't fullfilled from Sales Order or Backorder in Workflow

To clarify, are you asking if there's a way to restrict billing of an unfulfilled line on a SO? OTHER than the accounting preference to not allow billing ahead of fulfillment? I don't believe this would be possible via workflow so you'd need a developer to script this, if it's possible at all #notadeveloper

@JMS you can easily restrict items on the invoice that wasn't fulfilled. Go to Setup > accounting > accounting preferences > order mgmt > invoicing Under Order Management tab, uncheck the checkbox Show Unfulfilled Items on Invoice.

I already tried the 2 options in invoicing : SHOW UNFULFILLED ITEMS ON INVOICES, and INVOICE IN ADVANCE OF FULFILLMENT but @Tanu but I can't do partial invoice. Ex. 3 line items on Sales Order , 1 line item has been fullfilled- I only want that line item to be invoice. For now we manually remove other line items. Hope there's a quicker way for this so Accounting will not see items that are backordered

Hmmmm....what about just generating the invoice directly from the fulfillment? There should be a 'Bill' button on the Fulfillment that will generate an Invoice for JUST the items from the SO on that item fulfillment. Might not work based on your process but worth a crack