Every supply-house run in the middle of a job costs you the drive, the counter line, and usually the afternoon’s second job — call it $150–$300 of gone, in gas and missed labor, to buy a $6 fitting. The fix isn’t heroic memory. It’s a boring, written truck stock list with a “full truck” number for every item. Here’s a working starting point for a residential service truck, then the part nobody tells you: how to keep it stocked without counting.
The list, by category
Emergency stops & supply
- Quarter-turn angle stops, 1/2” × 3/8” (par: 10) — the single most-used part on a service truck
- Supply lines: faucet and toilet, braided (par: 8 each)
- SharkBite-style push couplings and caps, 1/2” and 3/4” (par: 6 each) — expensive per fitting, cheap per emergency
Toilet & faucet
- Wax rings (with and without horn) + brass closet bolts (par: 6)
- Universal fill valves and flappers (par: 6 each)
- Faucet cartridges for the three brands your market actually has (par: 4 each)
Drain
- P-traps and trap adapters, 1-1/4” and 1-1/2” (par: 4 each)
- Fernco-style flexible couplings, common sizes (par: 4)
- Cleanout plugs and caps, assorted (par: 6)
Copper / PEX / fixings
- Copper couplings, 90s and stops in 1/2” and 3/4” (par: 10 each); solder, flux, sandcloth
- PEX rings and fittings for your system of choice (par: 20 rings)
- Dielectric unions and water-heater flex connectors (par: 3 each) — the difference between a same-day water heater and a tomorrow one
Consumables
- PTFE tape (a whole sleeve), pipe dope, CPVC/PVC cement and primer, silicone, rags
Set two numbers per item: a par (what a full truck carries) and a min (the “order more now” alarm). The list above is a starting point — run it for a month and let your actual jobs correct the numbers. Your invoices already know what you use; that’s the point of the next section.
The system: stop counting, start subtracting
Paper lists die because they depend on someone counting a truck at 6 PM. The durable version inverts it: every part that goes on an invoice comes off the truck automatically. You counted the truck once; from then on the math does itself — the count only drifts when someone grabs a part without invoicing it, which is its own useful signal.
- Write the list (above) with par and min per truck.
- Count each truck once. That’s the last full count you do.
- Invoices subtract as jobs go out. Below-min items raise a hand.
- Restock day: fill to par, tap done. Low stock becomes the supply-house order — not a memory exercise.
This is exactly how FieldForge’s truck stock works: parts on sent invoices come off that tech’s truck by themselves, the owner sees every truck live with low-stock alerts, restocking is one tap, and anything below its minimum turns into a draft purchase order for your supply house in one click. The techs never count anything — which is the only reason any of it keeps working past week two. Free to start.