Pricing plumbing jobs with a flat-rate book

Most solo plumbers I talk to still price by the hour in their head: figure the job takes two hours, pick an hourly number that feels fair, add parts, and write it on the invoice at the truck. The problem shows up the day a fitting seizes, a shutoff crumbles, or the crawlspace is full of water. Now the job took four hours instead of two, and you either eat it or have an uncomfortable conversation on the customer’s doorstep. Flat-rate pricing moves that whole fight to before the work starts.

Build the book off your real cost

A flat-rate book is just every common task priced ahead of time: replace a fill valve, reset a toilet, swap a kitchen faucet, clear a lav drain, install a shutoff. Each task gets one price the customer sees, but behind it sits your math. Take the average labor time to do the task right (not your best time, your honest average), load your hourly cost with payroll tax, comp, and overhead, add the part at your marked-up cost, then add your target margin.

Do this exercise on jobs you have actually finished, not on jobs you imagine. Pull five recent tickets and back into what each one really cost you once you count drive time, the trip to the supply house, and the callback you did for free. That number is your floor. Price under it and you are paying to plumb.

Sell the outcome, not the hour

The homeowner does not want to buy your time, and honestly you do not want to sell it. Selling hours punishes you for being fast and rewards you for being slow, which is backwards. Flat-rate flips it: the price is for a working faucet, a toilet that does not run, a drain that flows. You quote it up front, they say yes or no before you touch a wrench, and the invoice at the end is exactly the number they already agreed to.

That up-front yes is the whole point. No surprise, no arguing over whether the job “should” have taken that long, no discount to make peace at the truck. When something unexpected shows up mid-job, you stop, show the customer, and quote the added task from the same book.

Keep the book alive

A price book you built once and never touch will slowly bleed you as parts and wages climb. Reprice the top twenty tasks at least twice a year, and immediately whenever a supplier raises a common part. Track your close rate too. If customers say yes to everything without blinking, you are probably leaving money on the table on the routine work.

For choosing the software that stores and presents your book on a tablet, see the field-service software guide. To find suppliers and vetted pros to sub the overflow, browse our directory.

When the job is not a book job

Repipes, remodels, and anything opened up behind drywall do not belong in the flat-rate book. Those get a written estimate with a stated allowance and a clear line on what triggers a change order. Trying to force a big renovation into a task-based price is how you end up giving away a week of labor.