I understand that item fulfillment is directly linked to the invoice but I believe there must be a way. I am creating a saved search that will count the number of shipments (Item Fulfillments) that are invoiced. We invoice based on item fulfillments.

I have never been able to join IF <> Inv except via the created from SO. IME when wanting to report on Inv & IF, I always start with a SO search (mainline= F) and join the other transactions.