A plumbing invoice gets handed over at the door or sent before the truck leaves the street. It needs the labor-parts split, your license number, and terms that say due on receipt — this one has all three filled in.
Due on receipt is the residential standard — the work is done and verified on the spot. For commercial property managers, Net 14 or Net 30 is common; agree before the work starts.
It depends on your state — parts are commonly taxable while labor rules vary widely. This template splits labor and materials so applying your state's treatment is straightforward. When in doubt, ask your accountant.
Yes, as its own line — and tell the customer about it when booking. Many plumbers credit it toward the repair if the customer proceeds; the invoice can show exactly that.
Switch this template to quote mode — same document, "Quote" instead of "Invoice", with a valid-until date. When the customer accepts, turn it back into the invoice in a few clicks.