How to Write a Plumbing Invoice: Service Calls, Parts, Tax

A plumbing invoice is read by three different people: a homeowner who wants to know why the bill is higher than the phone quote, a property manager matching it to a work order, and sometimes a warranty or insurance claims handler. Each needs the same thing: what was wrong, what you did about it, and what each part cost.

This guide covers the lines a plumbing invoice needs, two worked invoices (a service call and a water heater replacement), the Texas disclosure rule, how New York taxes different plumbing jobs, and where InvoiceQuickly fits. Prices in the examples are made up to show the arithmetic, not market rates. For setting your prices, see how to price plumbing services. For a field-by-field annotated sample, see the plumbing invoice example.

What should a plumbing invoice include?

The basics are the same as any invoice: your business details, the client, an invoice number, the issue and due dates, line items, the total and how to pay. The how to write an invoice guide covers those. For plumbing work, add:

• The job address and access notes, if different from the billing address. Landlords and property managers pay for many addresses.
• The complaint, the cause and the fix, in one sentence each. "Kitchen sink slow. Grease blockage 6 ft into the branch line. Cleared with cable machine and flushed." This line is what stops the "you just ran a snake" phone call.
• Arrival and finish times on hourly and after-hours work, so the hours can be checked.
• Each part on its own line, with quantity. For water heaters, softeners and pumps, add make, model and serial number. The client needs them for the manufacturer's warranty and you need them if it fails.
• Permit fees and inspection dates, shown as pass-through charges with the permit number.
• Disposal or haul-away of old equipment as its own line, because clients assume it is included.
• Your workmanship warranty, separate from the manufacturer's parts warranty, for example "Labour warranted 1 year from install date; unit covered by manufacturer's warranty". The period is your choice; state it.
• Your licence number. Some states require it on invoices, as Texas does below.

Worked example: a service call with the diagnostic fee credited

Hypothetical example. This plumber charges a $95 service call to diagnose a problem, and credits it to the repair if the customer approves the work on the same visit. The customer approves two repairs. Invoice issued on site, due on receipt:

Check: 0 + 185 + 180 + 28 = 393. Showing the credited service call at $0.00, instead of leaving it off, records that you diagnosed the problem and that the customer received the credit. If the customer had declined the repairs, the invoice would be a single $95.00 line.

Worked example: a water heater replacement with a permit

Hypothetical example. A homeowner's 40-gallon gas water heater has failed. The plumber replaces it with a 50-gallon unit under a city permit and invoices after the final inspection, due in 7 days:

Check: 150 + 1,100 + 1,350 + 165 + 125 = 2,890. Whether a sales tax line belongs on this invoice depends on the state, which is the next section.

Do plumbers charge sales tax?

It depends on the state and the type of job, and the same visit can contain both kinds. New York is a clear example. Its capital improvement test asks whether the work substantially adds value or appreciably prolongs the property's life, becomes part of the property, and is meant to be permanent. New York's own examples split plumbing work in two: "installing a hot water heater" is a capital improvement, while "replacing a thermostat on a hot water heater" is a taxable repair (New York State Department of Taxation and Finance, TB-ST-104 Capital Improvements, issued 27 July 2012).

New York's combined rate is the 4% state rate plus the local rate for the city, county or school district, plus 0.375% inside the Metropolitan Commuter Transportation District (NYS Department of Taxation and Finance, Sales tax rates). Use the department's lookup by address for the exact rate. Worked example at an illustrative 8% combined rate: a $240 thermostat replacement carries $19.20 tax (240 × 0.08), for $259.20. The $2,890 water heater invoice above, with a signed ST-124 on file, carries no tax line.

Other states draw different lines. Texas, for example, does not tax labour to repair a home but does tax repair work on commercial property. Check your own state revenue department's guidance for contractors. This is general information, not legal or tax advice. Last reviewed: 27 October 2026.

What must a Texas plumbing invoice show?

Texas has a specific display rule. The Responsible Master Plumber (RMP) of record and the plumbing company's owner must make sure the first page of every written or electronic proposal, invoice or contract shows, in at least 12-point font (22 Texas Administrative Code § 367.10(b), last amended effective 16 August 2020):

1. the RMP's first and last name;
2. the RMP's licence number;
3. the phrase "regulated by the Texas State Board of Plumbing Examiners"; and
4. the Board's mailing address, phone number and website (tsbpe.texas.gov).

The rule counts written estimates, service invoices, billing invoices and receipts as invoices. Copy the Board's current address and phone number from its website when you build your template, rather than from a third-party form.

How should property manager and work order jobs be billed?

Send one invoice per work order, with the work order number, the unit and the tenant's reported problem at the top, even if you also send a monthly statement. A property manager's accounts payable team matches each invoice to a work order, and a combined monthly invoice with six jobs on it often waits until someone checks all six. If a job needs approval above the client's not-to-exceed amount, put the approval reference on the line ("Approved over NTE by J. Patel, email 3 June"). Payment terms are usually set by the management agreement; the invoice payment terms guide explains Net 30 and other common terms.

Can you invoice plumbing jobs in InvoiceQuickly?

Yes, for straightforward service and replacement invoices. Know the limits first.

Available now:

• Line items with quantity × unit price (up to 100 lines), notes and terms, on every plan. A line can be $0.00, so a credited service call can stay visible.
• Type or say what you did and an AI draft fills the client, lines and terms into the editor for you to review before saving. Free includes 3 AI drafts; Pro is unlimited.
• One tax percentage and one discount percentage per invoice. Tax is added on top of the discounted subtotal.
• Recording full or partial payments (cash, check, card, bank transfer, other) on every plan. The Free plan includes 5 invoices and 5 clients.
• On Pro ($9/month): estimates the client can accept in their portal and convert to an invoice, email delivery, scheduled reminders before and after the due date, and Stripe or PayPal payment links through your own account for the remaining balance.

Not available today: a native mobile app or offline mode (it runs in the browser), a parts price book, per-line tax, attachments such as permit receipts or photos, dispatch and scheduling, and a deposit feature.

When is InvoiceQuickly not the right fit for a plumbing business?

• Texas plumbing companies. InvoiceQuickly's PDF prints line items, notes and terms in type smaller than 12 points, so you cannot meet the 12-point disclosure rule above with the PDF as it stands. Use a tool or template that lets you set the disclosure block's font size.
• Visits that mix taxable and nontaxable work, such as a New York water heater install plus a taxable repair. One tax rate applies to the whole invoice, so you would need two invoices for one visit.
• Shops running several trucks that need dispatch, a price book and card capture in the field. That is field service management software, not an invoicing tool.

Frequently asked questions

Should I charge a diagnostic fee if the customer approves the repair?

That is your policy to set, and it should be on the estimate. A common approach is to charge the service call whether or not the customer goes ahead, and credit it to the repair if they approve it on the same visit. Show the credit on the invoice as a $0.00 line so the record is complete.

How do I bill for parts: cost plus markup or a flat price?

Either works if the estimate says which. Cost plus a stated markup suits large or unusual parts the client may check. A flat installed price suits common repairs such as fill valves and faucets. For water heaters and other equipment, itemise the unit with make, model and serial number either way.

What if I find a bigger problem behind the wall?

Stop, photograph it, give the client the new scope and price, and get approval in writing before continuing. Bill the extra work as its own line with the approval date and method, for example "Additional repair approved by text 14:20, 3 June".

Do plumbers charge sales tax on labour?

It depends on the state and the job. In New York, installing a water heater is a capital improvement with no sales tax charged to the customer, while repairing an existing water heater is taxable. Check your state revenue department's guidance for contractors.

What licence information goes on a plumbing invoice?

In Texas, the first page must show the Responsible Master Plumber's name and licence number, the phrase "regulated by the Texas State Board of Plumbing Examiners" and the Board's address, phone and website, in at least 12-point font. Other states have their own rules. Showing your licence number is good practice everywhere.

Plumbing invoice template

Use the plumbing invoice template for service call, labour and parts lines, or the handyman invoice template for mixed small jobs. For contractor billing more broadly, see the contractor invoicing guide. More trade guides are on the InvoiceQuickly blog.

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