Two ways to price one job
Every service job is priced one of two ways. Flat rate: one number, set before the work, for a defined outcome. Time and materials: the customer pays for the hours worked and the parts used, at posted rates. Neither is the moral one. Each is honest when it is used where it fits and quoted before the wrench comes out.
Flat rate: the shop carries the risk
Under flat rate the customer knows the price before saying yes. That certainty sells. Nobody watches the clock, nobody dreads the total. In exchange, the shop carries the risk. The job that fights back (the seized fitting, the corroded flange) costs the shop, not the customer. The fast tech is the reward side of the same bet: the job that goes clean earns the shop the difference. Flat rate only works when the book behind it is priced on honest average time, not best-case time.
Check yourself
1 of 2
A flat-rate job runs three hours longer than planned. Who absorbs that?
T&M: the customer carries the risk
Time and materials fits work whose scope nobody can honestly know up front: diagnosis, old buildings, opened walls. The customer pays for what the job actually takes, so the risk of surprise sits with them. That is fair, but only with guardrails. Posted rates, an estimate of the range, and a not-to-exceed cap that stops the work for approval before the number runs away. T&M without an NTE is how trust dies on the final bill.
Where each one fits
Flat rate
Repeatable, known-scope work. The water heater swap, the drain clear, the fixture rebuild. The book already knows this job.
T&M
Discovery work. Diagnosis, intermittent faults, buildings with history. Nobody can honestly fix the price of the unknown.
The NTE bridge
T&M with a cap the customer approves. The fairness of hourly with a ceiling on the surprise.
Check yourself
2 of 2
A diagnosis call on a forty-year-old building with unknown scope. Which pricing fits, and what keeps it fair?
Most shops run both
This is not a religion to pick. Most healthy shops run flat rate on the repeatable work and T&M on the discovery work, and the estimate says plainly which one this job is before anyone says yes. The price book carries the flat-rate entries; the posted hourly and the NTE line carry the rest. The rule that matters is the same for both: the customer learns the shape of the bill before the work starts.