I am trying to make a "Balance" transaction body field that will display the balance left on purchase orders for vendors (Amount balance) I've made the body field and source listed Entity which I believe may be the problem, and sourced from "Balance Base" it displays on the purchase order a balance which I assume is the balance of their account not the balance of the individual purchase order. Thoughts/suggestions?

are you speaking of the unbilled amount or undelivered items?

The unbilled amount and undelivered items actually both, sorry for the delayed response!