Should I bill flat-rate or hourly?

Either works — flat-rate per task is cleaner for the customer and protects you on jobs that run long, while hourly suits open-ended diagnostics. The invoice should make clear which you used.

Do parts and labor need separate lines?

Yes. Separating them shows the customer what the materials cost versus your time, and it keeps your labor rate from looking inflated when a job needs an expensive part.

Should the diagnostic fee show on the invoice?

Yes, as its own line — and if you credit it toward the repair, show that credit so the customer sees they weren't double-charged.

Plumbing Invoice Template (Free)

Essential line items on a plumbing invoice

A professional plumbing invoice serves as a financial receipt, a work guarantee, and legal proof of plumbing code compliance:

Master Plumber Licensing Header: Business name, physical shop or van unit address, phone, email, state Master Plumber license number, and commercial liability insurance details.
Customer & Service Location: Client name, property address, and service date.
Dispatch & Diagnostic Surcharges: Initial trip fee, video camera drain inspection charge, or emergency leak diagnostic fee.
Itemized Repair & Installation Labor: Billed as flat-rate task pricing or hourly plumbing shop labor ($95–$175/hr).
Itemized Plumbing Materials: High-grade PEX-B/PEX-A tubing, copper press fittings, brass shutoff valves, PVC drain pipe, water heaters, and garbage disposals.
After-Hours / Emergency Surcharges: Weekend, holiday, or late-night dispatch surcharges.
Payment Terms & Workmanship Warranty: Payment due terms (Net 0 for residential calls) and written warranty duration.

Free Plumbing Text Template

Copy and paste the template below to format clear, professional plumbing invoices:

================================================================================
                    PLUMBING SERVICE INVOICE & RECEIPT
================================================================================
PLUMBING CONTRACTOR:                       INVOICE DETAILS:
[Your Plumbing Business Name]              Invoice Number: PLUM-2026-0742
[State Master Plumber License #]           Service Date: August 3, 2026
[Phone & Billing Email Address]            Payment Terms: Due Upon Completion (Net 0)

CLIENT & PROPERTY LOCATION:
Client Name: [Homeowner / Landlord Name]   Property: [876 Waterway Drive]

--------------------------------------------------------------------------------
LINE ITEM DESCRIPTION & SPECIFICATIONS                          AMOUNT
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1. Emergency Main Sewer Line Video Camera Inspection            $175.00
2. 50-Gallon Hybrid Electric Water Heater Installation (Labor)  $850.00
3. 50-Gal Rheem Hybrid Heat Pump Water Heater Unit (Model #50) $1,450.00
4. 3/4" Brass Ball Valves, Expansion Tank & Flex Lines          $185.00
5. Emergency Weekend Callout Surcharge                          $125.00
6. Diagnostic Inspection Fee Applied Credit                    -$75.00 (Credit)
--------------------------------------------------------------------------------
SUBTOTAL:                                                      $2,710.00
State & Local Material Sales Tax:                              $62.50
--------------------------------------------------------------------------------
TOTAL AMOUNT DUE & PAYABLE:                                    $2,772.50
--------------------------------------------------------------------------------

PAYMENT TERMS & WARRANTY STATEMENT:
Due Upon Completion. Accepted: Credit/Debit Card, Apple Pay, Cash, Check.
1-Year Workmanship Warranty on installed fixtures and piping connections.
Thank you for calling us for your plumbing needs!
================================================================================

Flat-rate task pricing vs. hourly plumbing diagnostics

Plumbing repair billing varies based on job predictability:

Flat-Rate Task Pricing (Standard Installations): Common plumbing jobs are best billed using flat-rate task pricing: Water Heater Replacement ($1,200–$2,800), Garbage Disposal Installation ($180–$320), Toilet Replacement ($220–$400), Main Line Drain Hydro-jetting ($350–$650). Flat-rate billing eliminates customer anxiety while rewarding fast, experienced plumbers.
Hourly Diagnostic Billing (Troubleshooting): Locating slab leaks, mysterious sewer odors, or hidden wall pipe corrosion requires open-ended diagnostic time. Charge an initial diagnostic/trip fee ($95–$175) that covers the first 45–60 minutes of investigation, crediting a portion toward the total repair if authorized.

Itemizing materials, PEX/copper fittings, and emergency surcharges

Transparent itemization prevents customer disputes and covers material inflation:

Plumbing Materials & Fixtures: Itemize major fixtures separately from installation labor. Apply a standard 25% to 40% markup on wholesale plumbing supplies to cover sourcing and vehicle inventory stock.
Emergency & After-Hours Callout Fees ($125–$250): Emergency calls outside regular business hours (5 PM – 8 AM, weekends, holidays) warrant an explicit emergency dispatch surcharge to compensate for overtime labor.

Driveway billing workflow: Paid before pulling out

Secure payment on-site before leaving the customer’s property:

System Pressure Test & Demonstration: Run water fixtures, inspect PEX press connections, and verify leak-free operation in front of the homeowner.
On-Site Payment Collection: Present the digital invoice on your smartphone or tablet. Collect credit card, debit card, Apple Pay, cash, or check payments on the spot before pulling out of the driveway.

If you bill trip charges on service calls, read how to charge a travel fee for out-of-area jobs. For annual testing work, see the backflow test invoice template, or compare invoicing apps for solo trades in our field service app under $20 a month breakdown.