How to write a plumbing invoice

Put each task, part and fee on its own line, subtract what the customer has already paid, and end with a due date and how to pay.

Plumbing invoice lines and units

Line	Unit	How it’s counted
Plumber labor	hr	Time on the job
Service call or trip fee	visit	Once per visit
Flat-rate repair	job	One price per task
Parts and fixtures	ea	Each item; model number for fixtures
Permit	ea	The fee, with the permit number
Disposal or haul-away	job	Old fixture, water heater or debris
After-hours	hr or visit	Night, weekend or holiday time

Name each line after the task and the place, such as “Replace wax ring and reset toilet, upstairs bath”, so the customer and any insurer can see what they are paying for. Keep labor and materials on separate lines. If the service-call fee is credited to the repair, say so on that line.

Deposits and earlier payments on the final invoice

Bill the whole job, subtract every earlier payment, such as the deposit and any progress payments, and show the balance due. For example, on a $3,000 job with a $300 deposit, the final invoice shows a $3,000 total, $300 paid and $2,700 due.

Progress, final and recurring plumbing bills

A service call gets one invoice when the work is done. On a remodel, repipe or new build, bill in the stages your contract sets, such as rough-in and finish, and show the contract price, what has been billed so far and what is left. Recurring maintenance gets one invoice per visit, with the service address on it.

Due dates and payment terms

Agree on terms before you start, and put a due date, written as a date, on every invoice. On a service call, payment when the job is done is simplest. Say how you take payment: the methods, who checks are payable to, and any payment link. Property managers often need their PO number on the invoice, so ask for it up front.

Sales tax on plumbing invoices

Whether plumbing labor, parts and fixtures are taxed depends on the state, and installed work can be taxed differently from a repair. Separate labor and materials lines let you treat each one correctly. Add a tax line only where your state has you charge it, and check your state’s sales tax guide first.

License numbers and other state requirements

Some states set rules for a plumber’s paperwork. A few examples, not a complete list:

• Texas: the first page of each proposal, invoice or contract for plumbing services, service invoices and receipts included, must show in at least 12-point font the first and last name and license number of the Responsible Master Plumber of record, the phrase “regulated by the Texas State Board of Plumbing Examiners”, and the Board’s mailing address, phone number and website (22 TAC §367.10(b)).
• License or registration numbers: California requires a licensed contractor’s license number in all construction contracts (B&P §7030.5), Florida a contractor’s registration or certification number in each offer of services, business proposal, bid and contract (Fla. Stat. §489.119), and Pennsylvania a home improvement contractor’s registration number on all contracts, estimates and proposals with owners (73 P.S. §517.6).
• Lien releases: California’s Contractors State License Board says that by law an owner may withhold the next payment until getting the unconditional releases for the previous one (CSLB). If suppliers or subcontractors worked on the job, have their unconditional releases for the previous payment, and conditional releases for this one, ready when you bill the next stage.

Three mistakes that delay payment

1. One lump-sum line. “Plumbing repairs” with a single price invites a phone call before anyone pays.
2. Extra work without a signed change order. Write up the second leak or the seized shutoff you found, with the added cost, and get it signed before you do the work. Some state or local laws limit how far the final bill can exceed the estimate unless the customer approved the increase (FTC, Hiring a Contractor).
3. A late or incomplete invoice. One sent days later, or missing the due date, the PO number or, in Texas, the Board details listed above, gives the payer a reason to wait. Write it before you leave the job.