Flat Rate vs Hourly Plumbing: How to Decide in 2026

The real question is not which one is "better"

Both pricing models can produce a profitable plumbing business. Most growing shops end up running both at the same time, with a service-call fee on top. The honest question is where the line goes between the two, and what the loaded hourly rate needs to be before either model can carry the shop.

The Bureau of Labor Statistics put the median annual wage for plumbers, pipefitters, and steamfitters at $62,970 in May 2024, the most recent full release.¹ That is the technician's pay, not the shop's billable rate. Loaded with employer-side payroll taxes, the truck, insurance, licensing, tools, and a realistic billable-hour ratio (more on that below), the floor for what the work has to charge is the same number under either model. The pricing model sits downstream of that math, not upstream.

So when an owner asks "should I switch from hourly to flat rate," the better question is: what is my loaded rate, what does my time data look like on the jobs I would put on a price book, and where am I bleeding money today that the other model would catch.

Why hourly quietly underprices the trade

Three structural problems make hourly the model that quietly leaks money for a one-truck shop.

The mental anchor. Most homeowners decide whether your hourly rate is "reasonable" by comparing it to their own hourly pay or to a number they saw on a search result. Published consumer-facing plumber rates for 2026 run roughly $75 to $200 per hour across the country.² A homeowner who earns $35 an hour at their day job is going to flinch at $175 an hour from the plumber, even when the job is skilled and the technician finishes in twenty minutes. The same homeowner will pay $385 to "replace the kitchen faucet" and not flinch at all, because the line item is for a thing, not for time.

The speed bonus goes the wrong way. Flat rate captures the upside when the job goes faster than the time it was priced on. Hourly hands that upside straight to the customer. The plumber who repairs a hose-bib leak in twenty-five minutes on hourly bills half an hour and goes home. On flat rate, the bill is what the job was priced at, and the speed bonus pays for the calls that ran long.

The billable-hour math is brutal for solo shops. Solo plumbers do not bill forty hours a week. Industry rule of thumb is closer to twenty to thirty, after travel, parts runs, quoting, callbacks, and unpaid follow-ups. The standard flat-rate-book planning number for service technicians is 1,000 billable hours per year (roughly 20 billable hours per week), and that is the number the flat-rate-book industry literature is built around.³ A one-truck shop running at $100 an hour and hitting twenty-five billable hours a week pulls in $2,500 a week before parts markup. On flat rate, where eight calls out of ten land at or above the time the line item was priced on, capturing the upside on the fast ones is the difference between making the shop work and watching the margin drift.

Where flat rate wins and where it bleeds you

Flat rate wins on standardized residential tasks where the on-site time is reasonably predictable. Drain clearing, faucet replacement, water heater swap-out, toilet install, garbage disposal swap, hose-bib repair, supply-line replacement, angle stop replacement. Every one of these is a job a one-truck shop has done dozens of times and has real time data on. Flat rate also wins on the sales call itself. The faster the shop can quote a fixed price on the phone or at the door, the higher the close rate, because the homeowner has already done the mental work of deciding whether they will pay the number before the technician unloads the truck.

Flat rate bleeds you on three kinds of work. First, jobs where the scope is genuinely unknown until you cut a wall or pull a fixture: slab leaks, mystery sewer odors, mixed-material repipes in older homes, second-floor leaks that have already done water damage you cannot see from the ceiling. Second, first-time work where you do not have time data; a flat-rate book built on guesses underprices the easy calls and overprices the hard ones, and the customer who got the overpriced one tells two people. Third, commercial work and insurance claims, where the customer wants itemized labor and parts for their own books and a single flat-rate line will lose the bid.

How to build a flat-rate book from your hourly base

A flat-rate book is not a list of guesses about what the market will bear. It is loaded labor times median on-site time, plus parts at markup, plus a per-task profit adder. Four ingredients, in this order.

Step 1: Compute your loaded hourly rate

Loaded hourly rate is the floor under every flat-rate line. Below it, every job loses money. Above it, the gap is profit. The formula is straightforward:

Loaded hourly = (annual cost of doing business) ÷ (billable hours per year)

Cost of doing business is every dollar the shop pays whether the phone rings or not: the technician's wage, employer-side payroll taxes, the truck (lease or depreciation, fuel, insurance, maintenance), liability insurance, workers' comp where required, licensing, tools, office expenses (phone, software, accounting), the dispatcher if you have one, and the profit margin you want the business to make. Billable hours is the realistic number, not the optimistic one. For solo shops, the 1,000 hours per year planning figure is a reasonable starting point and matches the flat-rate-book industry standard.³

For a solo plumber with $120,000 in annual cost of doing business and 1,000 billable hours, the loaded rate is $120. That number is the floor.

Step 2: Pull the time data

Open the last 100 invoices. For each repeating task (faucet swap, toilet install, water heater swap, drain clearing, disposal swap, hose-bib repair), write down the actual time on-site, not the time billed. Take the median, not the average. One outlier of a job (the faucet swap that turned into a corroded shutoff, a snapped supply line, and three hours at Home Depot) will skew an average and underprice every flat-rate line item that comes after it. The median is the right anchor because the customer is not paying for the outlier.

If the time data is not in your system, the next sixty days of invoices need it. Hand-write the start time and the stop time on every job, transcribe it in the evening, and use that data to build the book in the third month. Better to delay the book than to launch it on guesses.

Step 3: Build each line item

For each task:

Flat rate per task = median on-site time × loaded hourly + parts at retail markup + per-task profit adder

The parts column is its own line, not folded into labor. Industry standard markup for service plumbing parts runs 50 to 100 percent over wholesale on standard items, with higher markup on specialty fixtures or customer-ordered pieces.⁵ The per-task profit adder is the cushion that turns the loaded rate into a real margin instead of a break-even.

Step 4: Pressure-test the book

Take the new book to ten of your historical invoices. Compute what you would have charged on flat rate and compare it to what you billed hourly. If the flat-rate book is 10 to 20 percent below the historical hourly bills, your loaded rate is too low or your time data is wrong. Fix it before you quote a customer from the book. If the flat-rate numbers are within 5 to 10 percent of historical or above, you are in the right zone. Twenty to forty repeating tasks in the book is usually enough to cover 80 percent of the calls a residential service plumber runs in a month.

When to keep work on hourly

Some work stays on hourly even in a shop that runs a price book. The list is usually:

• Diagnostic and find-the-leak. The service-call fee covers the trip and the first 30 to 60 minutes of diagnostic time. See the companion guide on how to set a plumbing service call fee for the structure. Anything past the diagnostic block goes on the hourly clock, billed in 15-minute increments after the first hour.
• Cut-and-investigate work where the scope changes once the wall is open. The original quote carries a not-to-exceed cap, and any work past the cap requires a new written number before it proceeds.
• Commercial troubleshooting and old-building repipes where every joint and fitting is its own surprise.

The single most important sentence on a hourly quote is the not-to-exceed cap. "Not to exceed $X without written authorization to continue." That clause is what keeps an hourly bill from turning into a fight when the work runs fifty percent longer than the rough number. Without the cap, the bill is a fight every time the actual exceeds the verbal estimate, and the bill that is a fight is the bill that does not get paid.

Why the disclosure matters legally. The FTC's 2024 Rule on Unfair or Deceptive Fees, which took effect on May 12, 2025, requires that the total price a business advertises be clearly and conspicuously disclosed up front, and prohibits drip pricing and undisclosed surprise charges.⁴ The rule's text was written for live-event tickets and short-term lodging, but the underlying principle is the legal current that consumer-protection enforcement is moving with. A hourly bill that lands well above what the customer was verbally told to expect, with no written cap on the original quote, is the kind of bill that ends up in front of a state attorney general's consumer-protection desk. Put the cap in writing.

The hybrid model most growing shops settle on

The shape that comes up over and over: flat rate for the standard tasks in the price book, hourly with a not-to-exceed cap for genuine diagnostic and unknown work, and a service-call fee on top that covers the trip and the first thirty to sixty minutes on-site. The companion post on whether plumbers should charge for estimates walks the estimate-fee side of the same structure.

The hybrid is not a compromise. It is what the actual work looks like. A real day for a one-truck shop is three faucet swaps (flat), one diagnostic that ends in a found-and-fixed (service call fee plus hourly past the diagnostic block, or flat-on-completion if the fix is in the book), and one old-house repipe (hourly, capped). The dividing line is the predictability of the time, not the visibility of the work or the size of the bill.

The four-step migration if you are switching this quarter

A shop that wants to move from straight hourly to the hybrid model in one quarter can do it on this cadence:

1. Week 1: Pull time data. Reopen the last 100 invoices and write down the actual on-site time per task. Take the median for each repeating job. If the time data does not exist, start capturing it now and shift the rest of the schedule by sixty days.
2. Weeks 2 and 3: Compute the loaded rate. Add every cost the business pays whether the phone rings or not, divide by 1,000 billable hours (or your own measured number), and add the profit margin you want the shop to make. That is the floor.
3. Weeks 4 through 8: Build the book. Twenty to forty repeating tasks is enough for the first version. Each line is median time times loaded rate, plus parts at markup, plus a profit adder. Pressure-test against ten historical invoices before quoting a real customer from it.
4. Week 9 onward: Quote from the book on the relevant calls. Keep hourly with a written cap on the diagnostic and unknown work. Re-measure the actual time data once a quarter and revise the line items that are bleeding.

The migration falls apart at one of two places. Either the loaded rate is set on the technician's wage instead of the full cost of doing business (and every flat-rate line is now underpriced), or the time data is taken from optimistic memory instead of real invoices (and the book reads great on paper but loses money on the calls). Both failures are recoverable. Both compound if they are not caught in the pressure-test step.

Worked examples: a faucet swap and a slow-drain diagnosis

Both examples are illustrative for a hypothetical one-truck shop with a $120 loaded hourly rate. Substitute your own loaded rate, your own time data, and your own parts markup before quoting a real customer.

Example 1: Kitchen faucet swap, customer supplies the fixture

Median on-site time from the last thirty similar invoices: 1.25 hours. The math for the flat-rate line:

• Labor at loaded rate: 1.25 hours × $120 = $150
• Parts and supplies (mounting hardware, plumber's putty, supply lines): $18 at retail markup
• Per-task profit adder: $25
• Flat-rate line: $193, plus the service call fee

On hourly with the same median time and a published consumer-facing rate of $115 an hour, the bill would have been 1.25 × $115 = $144 in labor, plus small parts at or near cost (most plumbers do not mark up small parts on a hourly job), for roughly $156. The flat-rate version is higher because the customer is paying for a thing, not for time, and because the speed bonus on the calls that come in at one hour instead of 1.25 hours pays for the calls that take 1.75 hours instead. The median is the right anchor; the outliers cancel out across the book.

Example 2: Slow-draining master bathroom shower, customer reports a recurring slow drain for three weeks

Scope is unknown. Could be hair in the trap (fifteen minutes with a small auger), could be a partially collapsed branch line under the slab (three hours and a referral for a sewer camera scope). This is exactly the work that does not belong on a flat-rate line.

The right pricing structure:

• Service-call fee of $129 covers the trip and the first 45 minutes of diagnostic time.
• Hourly past the diagnostic block at $115 an hour, billed in 15-minute increments after the first hour past the block.
• Not-to-exceed cap of $450 on the diagnostic and clear-out attempt, without written authorization to continue.

On a fast diagnosis where the clog clears in twenty minutes, the bill is the service call fee, period. On a tougher one (90 minutes of diagnostic, two snake passes, a recommendation for a camera scope), the bill is $129 + (0.75 hours × $115) = $215.25, well under the cap. On the runaway case where the technician has spent three hours and still has not found the obstruction, the customer was on written notice before the second hour, and the conversation about authorizing a camera scope happens before the cap is hit, not after the bill arrives.

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Sources and further reading

1. U.S. Bureau of Labor Statistics, "Plumbers, Pipefitters, and Steamfitters: Occupational Outlook Handbook" (median annual wage $62,970, May 2024).
2. HomeGuide — 2026 Plumber Cost Per Hour; Angi — Plumbing Repair Cost (2026 data) (consumer-facing hourly ranges).
3. Flat-rate-book industry literature, see The New Flat Rate — "Building Your Own Plumbing Price Menu" (1,000 billable hours per year planning figure for service technicians, and the break-even calculation framework). Operator-side debate on this thread at Plumbing Zone — "Flat rate vs Hourly".
4. Federal Trade Commission, "Rule on Unfair or Deceptive Fees" (16 CFR Part 464, final rule effective May 12, 2025; principle: total price must be clearly and conspicuously disclosed, drip pricing and surprise charges are prohibited).
5. Plumber Magazine — "Should Plumbers Charge by the Hour or by the Job?" (trade-press framing of the model debate, including parts markup norms); Angi — Average general contractor markup.

This guide reflects general industry practices and 2026 U.S. plumbing pricing data. Worked example numbers are illustrative for a hypothetical one-truck shop and should not be used as a quote. Loaded rates, billable-hour ratios, parts markup norms, and the specific legal framework that governs how a plumbing business discloses fees vary by state and metro. Verify any specific number against your own cost-of-doing-business records, your accountant, your state contractor licensing board, and your state attorney general's consumer-protection guidance before you put it on a quote.