Plumbers face a unique inventory challenge. Most parts live on service trucks, not in a warehouse. That means tracking happens across multiple vehicles and multiple techs, often in real-time as parts get used on calls.

The simplest approach is using your field service software. Tools like ServiceTitan, Housecall Pro, or Jobber let technicians log parts as they use them on each job. The part gets recorded against the job, deducted from truck inventory, and syncs back to your accounting software. When this works well, you know exactly what was used where.

If you’re not using field service software, QuickBooks can handle basic inventory accounting. Set up each part as an inventory item with a reorder point. When you purchase parts, they add to inventory. When you use them on a job, assign them to that job so the cost shows up correctly. The limitation is manual entry. Someone has to record what goes on each truck and what gets used.

Truck stock replenishment is where most plumbing companies lose track. A tech grabs fittings from the warehouse, tosses them in the truck, and they never get recorded until someone notices the warehouse is empty. Create a simple checkout system. When parts move from warehouse to truck, log the transfer. When parts get used on jobs, log them against the job.

Regular physical counts keep your books accurate. Count truck stock weekly or at minimum monthly. Compare what you count to what your system shows. Discrepancies happen from unrecorded usage, parts left at job sites, or occasional theft. Finding the gap monthly is manageable. Finding it annually means you’ve lost thousands in margins you never knew were missing.

Organize truck stock so counting is fast. Bins and compartments by category make it easy for techs to grab the right part and easy to see when stock is low. A disorganized truck means longer counts, missed items, and techs buying parts at retail prices because they couldn’t find what they already had.

The real payoff for tracking parts is accurate job costing. A service call that looks profitable might not be when you add the actual material cost. If you’re guessing at parts or using averages, your job profitability numbers are fiction. Track parts at the job level and you’ll see which types of calls actually make money.

Most plumbers didn’t get into the trade to manage spreadsheets. But ignoring inventory means bleeding margin on every call without knowing it. Even basic tracking beats the alternative of finding out at year end that your material costs ate all your profit. For plumbing businesses along the Wasatch Front looking for help, bookkeeping services in American Fork that understand contractor needs can set up systems that work with how you actually operate.