If you run a plumbing company with three trucks on the road, you operate three mini-warehouses driving around your service area. And if you’re not doing proper truck inventory tracking, you’re leaking money in three different ways — and you can’t see any of it from your monthly P&L.
Truck inventory tracking is one of the most overlooked areas in trades bookkeeping. Most plumbing companies set up a single inventory account in QuickBooks, dump everything in, and call it good. That setup might work for a one-truck operation, but the moment you have multiple trucks, multiple techs, and hundreds of service calls per month, your inventory data becomes fiction.
Why Generic Inventory Tracking Fails for Plumbers
Here’s the typical failure pattern: a tech runs a service call, uses three brass fittings and a half-inch shutoff valve from the truck, writes the parts on a paper invoice or a field service app, and moves to the next call. The parts get billed to the customer (most of the time). The labor gets billed. The customer pays.
But the inventory deduction — the part where you reduce ‘inventory on hand’ and increase ‘cost of goods sold’ — frequently doesn’t happen, or happens in a delayed, batched way at the end of the month that doesn’t accurately reflect what’s on each specific truck.
Multiply that across hundreds of calls per month, dozens of part types, and several trucks. Within a year, your books say you have $40,000 in parts inventory while your trucks actually carry $12,000. The $28,000 gap is shrinkage, miscoded jobs, parts used and not billed, and a general loss of visibility.
The Real Cost of Inventory Drift
Inventory drift hits your business in three measurable ways. First, your gross margin per job looks artificially higher than reality, because parts costs aren’t fully flowing to the right jobs. Second, year-end physical counts reveal large variances that have to be written off — usually as a single ugly hit to your P&L. Third, you over-order. You can’t see what each truck actually has, so you keep buying.
None of these are recoverable with hindsight. The fix has to be structural.
Setting Up Truck Inventory Tracking the Right Way
Proper truck inventory tracking treats each truck as a separate inventory location in your accounting system. When parts are issued from your shop inventory to a specific truck, you record an inventory transfer — not just a ‘moved some stuff to the trucks’ note. When a tech uses parts on a job, the deduction comes from that specific truck’s inventory, not from the general inventory pool.
This requires three things working together: your accounting system has to support multiple inventory locations, your field service software has to capture parts usage at the job level, and your bookkeeping process has to reconcile them on a regular cadence.
| ✅ DIY: TRUCK INVENTORY SETUP CHECKLIST 1. Set up each truck as a separate inventory location in QuickBooks Online or your accounting system 2. Establish a ‘shop inventory’ location for parts not yet assigned to a truck 3. Record transfers from shop to truck as inventory transfers (not expenses) 4. Capture parts usage at the job level via your field service software 5. Reconcile each truck’s on-hand inventory monthly (not annually) with a physical count 6. Investigate variances over a threshold (suggested: 5% of truck inventory value) 7. Adjust restocking patterns based on actual usage data, not gut feel |
The Bottom Line
Truck inventory tracking isn’t glamorous bookkeeping work, but it’s the kind of operational discipline that separates plumbing companies that scale profitably from the ones that hit a revenue ceiling because they can’t see where their money is actually going.
BKKPRS builds bookkeeping systems for plumbing and trades businesses that treat truck inventory the way it should be treated — as multiple real inventory locations, tracked at the job level, reconciled regularly. If your books treat your fleet as a single inventory black box, we should talk. Visit bkkprs.com.
📎 Source: BDR — 30 Home Service Industry Trends for 2026
