Self-Employed Plumber Tax Deductions: 2026 Schedule C Guide to Tools, the Van, and Your License

Published: June 11, 2026 · Reading time: 8 min

TL;DR: A self-employed plumber's biggest write-offs are the van (Line 9 — $0.725/mile in 2026, or actual expenses for a heavily-equipped van), major equipment like drain machines, press tools, and inspection cameras (Section 179 on Line 13), and materials — pipe, fittings, fixtures, solder — on Line 22 for time-and-materials work or in Cost of Goods Sold for fixed-bid jobs. Liability insurance and bonds go on Line 15, license renewals and permits on Line 23, and PPE, code books, and continuing education on Line 27a. Plumbing is not an SSTB, so the 20% QBI deduction applies without the service-business phase-out.

Plumbing is a deduction-dense trade: thousands of dollars of equipment, a van full of brass, daily supply-house runs, licenses in every jurisdiction you pull permits in. Every legitimate dollar belongs on a specific Schedule C line — here's the map.

Line 13: Drain Machines, Press Tools & Cameras (Section 179)

Major equipment is a capital asset, but in practice you'll rarely depreciate it slowly:

Drain cleaning machines — sectional and drum machines, jetters
Press tools and crimpers (the four-figure battery kits)
Sewer inspection cameras and locators — often the single most expensive item in the van
ProPress jaws, threading equipment, core drills, pipe stands

Under Section 179, you can generally expense the full cost in the year the equipment is placed in service, on Line 13. Bonus depreciation is the alternative route, and for small purchases the de minimis safe harbor lets you expense items under $2,500 per invoice directly as supplies without touching depreciation at all.

Hand tools — wrenches, torches, tubing cutters — are ordinary Line 22 supplies in the year purchased.

Line 9: The Work Van

The van is usually the biggest single number on the return. Two methods:

Standard mileage: $0.725 per business mile in 2026 — simple, and it bakes in fuel, insurance, repairs, and depreciation.
Actual expenses: fuel, insurance, repairs, tires, registration, and depreciation × business-use percentage. A racked-out van used ~100% for the trade often wins here, and a heavy van (over 6,000 lbs GVWR) may qualify for accelerated Section 179 treatment.

The choice locks in partially — read standard mileage vs actual expenses before the first year's return. Either way you need a contemporaneous mileage log, and remember the first drive from home to a regular shop can be commuting — though service calls from a qualifying home office generally aren't. Tolls and parking stack on top of either method — details here.

Line 22 vs. Part III: Pipe, Fittings & Fixtures — Supplies or COGS?

How you bill decides the bucket:

Time and materials: supply-house purchases — PEX, copper, fittings, solder, wax rings, supply lines — are Line 22 supplies, deducted when purchased.
Fixed-bid jobs with significant materials — a repipe, a water-heater install with the unit in the price — belong in Cost of Goods Sold (Part III), matched against the job revenue.

Most plumbers run both patterns in a year; the total deduction is usually the same either way, but be consistent. The same split applies to electricians and handymen.

Line 15: Insurance & Bonds

Plumbing carries real liability, and all of it is deductible on Line 15:

General liability insurance — often required for the license itself
Surety/contractor bonds required by the state or municipality
Commercial auto for the van (actual-expense method only — it's inside the standard mileage rate otherwise)
Tool and equipment coverage (inland marine)

Health insurance is not Line 15 — premiums go on Schedule 1 via the self-employed health insurance deduction.

Line 23: Licenses, Permits & Registration

Line 23 collects the regulatory overhead:

Journeyman or master plumber license renewals
Backflow prevention certification, gas-fitting endorsements
Per-job permit fees pulled with the city or county
Business licenses and local registrations

If you pass a permit fee through to the customer and it shows up in your gross receipts, deduct it here so it nets out.

Line 27a: PPE, Code Books & Continuing Education

The catch-all Line 27a (itemized in Part V) covers:

PPE — gloves, eye protection, knee pads, respirators for solder and sewage work
Code books — UPC/IPC editions, local amendments
Continuing education hours required for license renewal, code-update classes
Trade association dues (PHCC and similar)
Answering service or booking software for dispatch

The line between deductible and not: education that maintains or improves your existing trade is deductible; the schooling that qualified you for the trade in the first place is not.

Other Lines Plumbers Use

Line 8 — Advertising: truck wraps, Google Local Services ads, lead-gen fees
Line 11 — Contract labor: the helper you 1099 on big jobs
Line 17 — Legal & professional: the CPA, lien filings
Line 20 — Rent or lease: shop or storage unit rent, excavator rentals
Line 21 — Repairs & maintenance: fixing the drain machine, not upgrading it
Cell phone (business percentage) on Line 25 — Utilities
Line 30 — Home office if the books, scheduling, and bids happen in a dedicated space

Plumbers and the QBI Deduction

Good news: plumbing is a trade, not a specified service trade or business, so the 20% QBI deduction applies without the SSTB phase-out that hits consultants and brokers at higher incomes. The deduction is 20% of qualified business income — profit after every Schedule C expense — so the tracking discipline above feeds directly into it.

Frequently Asked Questions

What can a self-employed plumber write off on taxes?

A self-employed plumber filing Schedule C can deduct drain machines, press tools, inspection cameras, and other major equipment (usually expensed in full under Section 179 on Line 13), pipe, fittings, fixtures, and consumables as supplies on Line 22 or as Cost of Goods Sold on bid jobs, the work van on Line 9 using either the standard mileage rate of $0.725/mile for 2026 or actual expenses, liability insurance and bonds on Line 15, license renewals and permit fees on Line 23, and PPE, code books, continuing education, and trade association dues on Line 27a.

Is my work van deductible as a plumber?

Yes — the van is usually a plumber's biggest deduction. You choose between the standard mileage rate ($0.725 per business mile in 2026) and the actual expense method (fuel, insurance, repairs, depreciation, multiplied by business-use percentage). A van fitted with permanent racking and used essentially 100% for the trade often does better under actual expenses, and a heavy van may qualify for accelerated Section 179 treatment. Whichever method you use, the IRS expects a contemporaneous mileage log with date, miles, destination, and business purpose.

Are pipe and fittings supplies or Cost of Goods Sold for a plumber?

It depends on how you bill. If you charge time and materials, supply-house purchases are deductible as supplies on Line 22 in the year you buy them. If you bid fixed-price jobs where materials are a significant component — a repipe, a water heater install with the unit included — the materials belong in Cost of Goods Sold in Part III, matched to the job revenue. Many plumbers have both patterns in the same year. The wrong bucket rarely changes the total deduction, but consistency matters and COGS done right keeps gross margin numbers meaningful.

Can I deduct my plumbing license and continuing education?

Yes. Journeyman or master plumber license renewals, backflow certification, gas-fitting endorsements, business licenses, and per-job permit fees are all deductible on Schedule C Line 23 (taxes and licenses). Code-update classes, continuing education hours required to keep your license, code books, and exam fees for additional endorsements go on Line 27a as other expenses. The one thing you cannot deduct is the education that qualified you for the trade in the first place — apprenticeship-to-license costs that qualify you for a new trade aren't deductible business expenses.

Does a plumber qualify for the QBI deduction?

Yes. Plumbing is a trade, not a specified service trade or business (SSTB), so the 20% qualified business income deduction isn't subject to the SSTB phase-out that hits consultants, brokers, and similar fields at higher incomes. A profitable self-employed plumber generally deducts 20% of qualified business income, subject to the regular taxable-income limits. The deduction is computed after Schedule C, so accurate expense tracking still drives the number — QBI is 20% of profit after every legitimate write-off.

Authoritative References

Track Every Supply-House Run

Five supply-house stops a day means five thermal receipts fading in the van. CentSense scans each one with AI the moment you get it — vendor, date, and amount extracted, tagged to the right Schedule C line — and logs your service-call miles at the 2026 rate of $0.725/mile. In April, export one CPA-ready CSV. Free tier includes 10 AI scans per month; Solo is $5/month for unlimited scanning and mileage logging.

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This guide is general education for U.S. freelancers and Schedule C filers in 2026. It is not personalized tax advice — bring your specific situation to a CPA or EA.

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