Bookkeeping for Plumbers and Remodelers: Job Costing and Tax Records

Bookkeeping for plumbers and remodelers comes down to four habits: keep business money in its own accounts, track the costs of every job against what you charged for it, record subcontractor payments so you can file 1099s, and set aside tax from each payment as it arrives. Get those four right and the rest (deductions, quarterly payments, your tax return) mostly falls into place.

This guide is written for solo plumbers, handymen who do plumbing and remodeling, and small remodeling crews with a few helpers or regular subcontractors. It covers how to set up your books, how to job-cost a remodel with real numbers, how to record deposits and retainage, when you need to send 1099s, and which deductions trades businesses miss most often.

Why Is Bookkeeping Different for Plumbers and Remodelers?

Most freelancers get paid after they finish the work and spend little up front. Trades work runs the other way. You buy fixtures, pipe, tile and lumber before the customer pays the final invoice; you collect deposits for jobs that haven't started; you bill in stages on larger remodels; and the scope changes halfway through when the customer adds a heated floor or you open a wall and find rotted framing. A single bank balance can't tell you whether you're making money, because it mixes next month's deposits with last month's material bills.

Plumbing service work adds its own wrinkle: lots of small tickets, parts pulled from stock on the truck, and a mix of card, check and payment-app income. Remodeling adds subcontractors, permits, dumpsters and longer jobs that can cross from one tax year into the next. Both need books that track money by job, not just by month.

How Should a Plumber or Remodeler Set Up Their Books?

Start with a business checking account and a business credit card used only for the business, so your statements become your expense records. Then use categories that match how the money actually moves in a trades business and map cleanly to Schedule C:

Truck stock deserves its own category. Parts you buy in bulk and keep on hand may need to be deducted when you use them on jobs rather than on the day you buy them, depending on how your business accounts for materials and supplies. Keeping them separate from job materials makes that easy to sort out at tax time, and our CPA can tell you which method fits your business.

How Do You Job-Cost a Remodel?

Job costing means recording every cost that belongs to a job against that job's price, so you know its gross profit when it's done. You don't need special software to start: a job name or number on every receipt, invoice and subcontractor payment is enough, as long as you do it consistently.

Here's a worked example with made-up numbers. A small remodeling crew signs a bathroom remodel for $26,200. Midway through, the homeowner adds a heated floor as a $1,800 change order, bringing the job to $28,000.

That $8,700 isn't take-home pay. It still has to cover overhead (insurance, the truck, licenses, your phone and tools) and then income and self-employment tax. But it tells you something a bank balance never will: whether this kind of job, at this price, is worth taking again. Compare gross margin across jobs and you'll quickly see whether small service calls, full remodels or change orders are carrying the business.

Two habits keep job costing accurate. First, write up every change order with a price before doing the work, and add it to the job's price as soon as the customer agrees, so it doesn't get lost in a final payment. Under the cash method, it counts as income when the customer pays it, not when you bill it. Second, tag subcontractor and material costs for the change order to the same job, so the extra work shows its own profit.

How Should You Record Deposits, Progress Payments and Retainage?

Under the cash method, income counts when you receive it or when it's made available to you without restriction (IRS Publication 538). Most solo plumbers and small remodeling crews use the cash method, so a deposit is income in the year it lands in your account, even if the work happens next year. Here's how the example remodel might be billed:

The tax-year edge case catches a lot of contractors: if you collect the $7,860 deposit in December 2026 for a job that starts in January 2027, that deposit is 2026 income, while most of the material and subcontractor costs land in 2027. Plan for it when you estimate which quarter income counts in, and record deposits with the job name so you can see which jobs you've been paid for but haven't finished.

Retainage works the same way in reverse. If a general contractor holds back 10% until the job is signed off, a cash-method subcontractor counts that 10% when it's actually paid, not when the work is done. Track retainage owed to you as its own list so it doesn't get forgotten.

Businesses on the accrual method follow different rules, and the IRS has separate rules for long-term construction contracts that span tax years, including the percentage-of-completion method. Small contractors and home construction contracts are generally exempt from those rules (see the Form 8697 instructions), but if you're growing or regularly run jobs across year-end, ask our CPA which method applies to you.

Do You Need to Send 1099s to Your Subcontractors?

Yes, for most unincorporated subs you pay enough. For payments made in 2026, the IRS reporting threshold for Form 1099-NEC is $2,000 per recipient for the year, up from $600 for payments made before 2026. The forms for 2026 payments are due February 1, 2027, because January 31 falls on a Sunday. One exception to the threshold: if you withheld federal income tax from a sub under the backup withholding rules, usually because they didn't give you a taxpayer ID, you must file a 1099-NEC for them whatever the amount.

• Collect a Form W-9 before the first payment. It gives you the sub's taxpayer ID and shows whether they're a sole proprietor, an LLC taxed as a partnership or corporation, or a corporation.
• Corporations are generally excluded. An LLC that's taxed as an S or C corporation generally doesn't get a 1099-NEC; a single-member LLC taxed as a sole proprietorship does.
• Card and payment-app payments are excluded. Payments you make by credit card or through a third-party payment network don't count toward your 1099-NEC totals. Any Form 1099-K reporting on them is handled by the card company or payment network, not by you.
• Track each sub's running total. A tile setter you pay $700 three times has crossed $2,000, even though no single payment did.

Our step-by-step guide to issuing and filing a 1099-NEC covers IRIS e-filing, penalties and proof of delivery.

One more check: a helper who works only for you, on your schedule, with your tools, may be an employee rather than a subcontractor, which means payroll and withholding instead of a 1099. The IRS explains the factors on its independent contractor or employee page. If you're unsure about a regular helper, talk to our CPA before year-end.

Which Deductions Do Plumbers and Remodelers Miss?

The deductions plumbers and remodelers most often miss or claim wrong are the work vehicle (standard mileage or actual costs for the business-use share), tools costing $2,500 or less per item or invoice, larger equipment deducted through Section 179 or bonus depreciation, and recurring costs such as licenses, surety bonds and liability insurance. Materials and subcontractors usually get deducted without a problem.

Your Van or Truck: Mileage or Actual Costs

The IRS set the 2026 business standard mileage rate at 72.5 cents a mile for January 1 through June 30, then raised it to 76 cents a mile for July 1 through December 31 because of higher fuel prices. Use the rate in effect on the date of each trip. The alternative is to deduct actual costs (fuel, repairs, tires, insurance, registration and depreciation) for the business-use percentage of the vehicle. A loaded plumbing van that burns a lot of fuel and needs frequent repairs often does better on actual costs; a lighter truck driven long distances may do better on mileage.

Either way, you need a mileage log, and driving from home to a job site and between job sites is generally business mileage if your home is your principal place of business. Be careful with the order of choices: if you claim Section 179, bonus depreciation or accelerated depreciation on a vehicle, you can't switch that vehicle to the standard mileage rate in a later year (IRS Publication 463). Passenger vehicles and SUVs also have their own depreciation caps; for 2026 the Section 179 limit for SUVs is $32,000. Confirm how your van or pickup is classified with our CPA before expensing it.

Tools and Equipment

Under the IRS de minimis safe harbor, a business without audited financial statements can expense tangible property costing up to $2,500 per item or invoice. You elect it each year with a statement attached to your return, and your books need to follow the same policy. That covers most drills, saws, press tools and pipe cutters.

For bigger purchases, two rules often let you deduct the full cost in the year you start using the equipment. Section 179 allows up to $2,560,000 of qualifying property for 2026, reduced once total purchases pass $4,090,000 (Rev. Proc. 2025-32), but it can't exceed your business income for the year. Bonus depreciation is now a permanent 100% for qualifying property acquired after January 19, 2025 (IRS Notice 2026-11). Which one is better depends on your income and plans, so a large purchase is worth a quick conversation with our CPA first.

Do Plumbers and Remodelers Charge Sales Tax on Materials?

It depends on your state, and sometimes on the type of job. In many states, a contractor who installs materials into a customer's home is treated as the end consumer of those materials: you pay sales tax when you buy them and don't charge sales tax to the customer. Other states let contractors buy materials tax-free with a resale certificate and then charge sales tax on materials listed separately on the invoice. Some states treat repairs differently from remodeling, and a few tax certain labor.

Check your state revenue department's guide for contractors, and set up your books to match: if you pay tax on materials, it's part of your material cost; if you collect it from customers, record it as money you owe the state, not as income.

How Much Should You Set Aside for Quarterly Taxes?

No one withholds tax from customer payments, so plumbers and remodelers who are sole proprietors or single-member LLCs pay quarterly estimated taxes on their profit. A common starting point is your expected income tax rate, plus about 14.1% for self-employment tax (15.3% on 92.35% of net profit), plus state income tax.

The trap for trades businesses is setting aside tax on deposits rather than profit, or not setting any aside until the job is finished. Using the example remodel, setting aside 25% of the full $28,000 would put $7,000 aside on a job that produced only $8,700 of gross profit before overhead. Base your set-aside on each job's profit as the customer pays, and move it to a separate savings account right away. The Safe-to-Spend method walks through how to do that with uneven income.

Remodeling income is often seasonal, and the IRS payment periods aren't equal quarters, so check which months each estimated payment covers. The next payment, for September through December 2026, is due January 15, 2027.

How Numeris Ledger Fits Here

Numeris Ledger connects to your business bank and card accounts and automatically imports and categorizes transactions as they come in: supply house purchases, subcontractor payments, fuel, insurance and customer deposits. You can start categorizing your job expenses in minutes, upload receipts so material and tool purchases are documented, and see your running tax estimate and Safe-to-Spend balance update as payments land, so a big deposit doesn't look like money you can spend. At year-end, Numeris Ledger prepares 1099-NEC forms for the subcontractors you paid.

Frequently Asked Questions

The information in this post is for general educational purposes only and does not constitute tax or legal advice. Consult our CPA for guidance specific to your situation.