A plumbing invoice has a harder job than most trades’ paperwork: half of what you fixed is inside a wall, under a slab, or down a cleanout where the customer will never see it. The invoice is the only proof of work they can hold. Here’s what a good one looks like — and if you’d rather build one than read about it, our free invoice generator runs in your browser, no signup.
The eight things every plumbing invoice needs
- Your business block. Name, phone, email — and your plumbing license number. Most states require it on customer paperwork, and even where they don’t, it separates you from the guy on Craigslist.
- An invoice number. Any consistent scheme (1042, JOB-118). When the property manager calls about “that toilet invoice,” you both need one word that names the document.
- The service address and date. The address where the work happened, not the billing address. Landlords with six rentals pay from paperwork that names the property.
- Itemized fixtures and parts. “Wax ring + brass closet bolts: $18” and “3/4” PRV, Watts N45B: $96” beat “parts: $114.” Itemizing kills the “what am I even paying for” call — and on repipes and remodels, it’s what gets you through the insurance or escrow review without a phone call.
- Labor on its own line. Hourly or flat-rate, either works (we compare the two here) — but keep it separate from parts. Bundled totals invite haggling.
- Photos of the work they can’t see. The plumbing-specific one. A before/after photo of the corroded section you cut out, the cleanout you jetted, or the slab leak you found is worth more than any paragraph of description. Attach them to the invoice record even if they don’t print — when the “you never fixed it” call comes, the photos end it.
- Permits and inspections, listed. Water heater swaps, repipes and sewer work often carry a permit fee. Put it on its own line with the permit number. Customers pay fees they can see; they fight fees buried in a lump sum.
- Payment terms and a way to pay. “Due on receipt” plus a payment link or card option. The day you send the invoice matters more than anything written on it — an invoice texted before your van leaves the curb gets paid while the fixed drain still feels like a miracle.
Water heaters get the equipment treatment: write the model and serial number on the invoice. Tank warranties run 6–12 years, and the customer will not know where their paperwork is. You will. That’s a service call, a warranty claim you can process, and a customer for life.
Estimates deserve the same rigor
Everything above applies to estimates, clearly labeled “ESTIMATE — this is not a bill.” On bigger tickets (water heaters, repipes, sewer lines), an itemized estimate with a deposit collected at approval separates the serious shop from the two other quotes on the fridge.
The part where we save you the typing
You can do all of this in the free generator — it remembers your business info on your device and prints a clean PDF. But if you’re writing more than a couple of invoices a week, typing them on a phone in a crawlspace is the real bottleneck. FieldForge removes it: hold a button and say “replaced the wax ring and reset the toilet, snaked the branch line, two hours labor” and the invoice builds itself from your price book and texts the customer a payment link. Free to start, in English and Spanish.