A clear invoice separates the agreed lump-sum freight from additional items. Each item should identify the shipment, service period, cause, calculation and proof. For a toll, the route and payment record may be relevant. For waiting time, record the start, end, place and cause. For a detour, identify the original and actual route.
The invoice cannot replace the legal basis by using a new label. “Special run”, “expenses” or “surcharge” does not by itself establish a claim. Conversely, an additional item may be justified where the price agreement excludes it or a valid instruction caused documented expenses.
Check credits, part payments and objections as well. The outstanding amount should be understandable from the agreed freight, accepted additional costs and items already settled.